Strengths:
The most durable troops
Excellency in castle defenses (dendroid special)
Three anti-magic specials
Castle special (Treasury) is cumulative and can sometimes achieve great results.
Both defender fighters have benefically increased growth rate.

Weaknesses:
Only one shooter and two flyers (and one of them quite vulnerable), however the shooter is a good one and the flyers are both pretty fast...

Army evaluation:
Centaurs 5/3/8/2-3/6/70
Centaur captains 6/3/10/2-3/8/90
Those fast warriors carry a good offensive punch. In high numbers they're far more important than you'd expect from a 1stlevel troop.

Dwarves 6/7/20/2-4/3/120, 20% magic resistance
Battle Dwarves 7/7/20/2-4/5/150, 40% magic resistance
Dwarves make a sturdy defensive unit, but after upgrade, they can be used even in offensive.

Elves 9/5/15/3-5/6/200
Grand Elves 9/9/15/3-5/7/225, shoot twice
In decent numbers, they provide you with much needed ranged firepower, but they need to be protected.

Pegasi 9/8/30/5-9/8/250, enemy has spell costs higher by 2
Silver Pegasi 9/10/30/5-9/12/275, enemy has spell costs higher by 2
Quite capable offensive unit with a handy special, esp. against weak scouts.

Dendroid Guards 9/12/55/10-14/3/350, binding attack
Dendroid Soldiers 9/12/65/10-14/4/425, binding attack
An excellent defensive unit with a special that has great tactical value.

Unicorns 15/14/90/18-22/7/850, blinding attack, magic aura
War Unicorns 15/14/110/18-22/9/950, blinding attack, magic aura
Tough and fast fighters. Magic aura gives adjacent units 20% magic resistance (the unicorns don't get the resistance bonus themselves.)

Green Dragons 18/18/180/40-50/10/2400+1c, immune to spells 1-3
Gold Dragons 27/27/250/40-50/16/4000+2c, immune to spells 1-4
Dragons are pretty strong and green ones also easier to get.

Upgrading priorities:

• Centaur Captains: High - increased durability and speed boost are worth it.
• Battle Dwarves: Low. Their value lies in magic resistance, but it's not so common for them to be primary target for spellcasting.
• Grand Elves: High, for the double shot and speed bonus.
• Silver Pegasi: High, for the speed boost that gives them access to enemy side in one turn.
• Dendroid Soldiers: Low. They're best used in castle defenses, as they can effectively 'block' holes in walls with their special ability.
• War Unicorns: High, for the +2 speed and increased HPs
• Gold Dragons: Very High, for the +6 speed, +9 A/D and +70 HPs.

Castle building in the first week:

Day 1:	Town Hall	2500g
Day 2:	Homestead	1500g + 10w
Day 3:	Enchanted Spring	2000g + 10c
Day 4:	Dendroid arches	2500g
Day 5:	Unicorn Glade	4000g + 5w + 5o + 10g
Day 6:	reserve
Day 7:	Citadel	2500g + 5o

Centaur stables as 1stlevel dwelling assumed present. If it's not present, we use the reserve slot to shift the schedule.
Usually the reserve would be used for Dwarf cottage, but as dwarves aren't a crucial unit in offensive strategies, you might want to go for something else (i.e. a mage guild, if your main hero is a ranger and you want him to get a spell book fast.)
Under extremely positive conditions, you might be able to buy Dragon Cliffs. However, you need two levels of mage guild, so you'd have to skip Town Hall and Citadel from the above schedule. And them extremely positive conditions are extra 14 crystal and extra 25 ore. No need to mention that it is worth is, sacrificing some gold chests to get two dragons on the beginning of second week - they'll allow much faster exploration, as they can battle many medium wandering armies without fear.

Resource summary:
You'll need 15w, 10o and 15000g, which leaves us (20000 + 7000 - 15000) = 12000g for Day 1 to spend on troops. I suggest the reserve day being used for homestead upgrade and day1 of second week be used for centaur stables upgrade - those will consume another 15w (thus making your requirements 10 wood above starting 20) and 2500 gold. With 9500g, you'll easily purchase all the centaurs (35x90) and elves (17x225) and all 12 pegasi, too. That is a decent exploration force. If you don't need the pegasi, save the gold for economic structures!
If, for some reason, you don't go for Unicorn Glade, I recommend upgrading Pegasi instead (if you find extra 5 crystal) and getting 1st level of mage guild (for the same gold, wood and ore consumption as unicorn glade).

Second week strategies:
Since there are no building variants, the second week will be easy - get some wood and raise City Hall, possibly Castle and Capitol or some of the beneficial buildings, while your main hero will look for gold and crystal sources.

Troops cost weekly (with castle):
Without 7th level: 18620
With 7th level: 26620
With one castle producing 14000/week, you see that you'll have to decide which units to left unpurchased. Dendroids and Dwarves are favorites, of course. Capitol at 28000/week will have minor surplus.
HPs grown weekly 2150 (plus 500 in Gold Dragons) at 8.66 g/HP (10.05)
[This is the highest HP total/week and lowest g/HP rating among all towns!]

Benefits:

• Blacksmith: First Aid Tents sold here.
• Dendroid saplings: +2 dendroids growth (not bad, just in case)
• Mystic Pond: gives 1-4 random resources each week. A good thing for longer games.
• Fountain of Fortune: Upgrade to mystic pond, gives +2 Luck when under siege. I never build it.
• Miner's Guild: +4 Dwarves growth (just as good as dendriod saplings), required for treasury.
• Resource Silo: Provides +1 crystal/day - a must if you don't have the mine!
• Treasury: On day 1 of each week increases your gold reserve by 10% - Great! Great! But be careful, the game can't handle total gold hihger than 10,000,000 ;-)

Strategy
You won't have much to worry for. Of course, wood is always needed for the City Hall and Castle, but you can relax in the first week.
A good strategy might also be to upgrade centaurs quickly, hire a few extra heroes that come with centaurs and with some 60-80 centaur captains run into some action - they're durable and offensive enough to handle even strong enemies. With their high speed, they can rely on 'waiting' to get two consecutive shots. But since AB, 3rd+ hero in any week will not come with any good starting army.

Forces combination:
In general, Dendroids and Dwarves should be kept home as castle defenses, possibly unpurchased. Of course, against particularly well-defended castles you might decide to use them - dendroids can be used to block an enemy that went after your elves or any other unit. They can take a lot of damage and you have a +2 growth benefit option on them.
A good strategy could be to use either dwarves or dendroids as sort of expendable fighter unit - and whenever their stack would get crippled, you'd switch for the other one, while the first would sit in the castle and grow silently and slowly back to some reasonable numbers.
The offensive force should be Centaur Captains, Silver Pegasi, Grand Elves and War unicorns. All are pretty fast and therefore you should use 'wait' against all walkers/flyers and even against shooters, unless your morale is very high and you count on it.
Green dragons are wimps that should be in later game used only in hopeless situations such as castle defenses. Upgrade them ASAP.
If for some reason your dwarves and dendroids hit the action out there, try to have first strikes with dendroids - they can absorb much more damage. Also, when all the enemy walkers/flyers attack them, the dwarves can with a little help of Haste start quickly to the other side to demolish shooters and/or war machines. The dendroids will take losses, but the effect should still be positive. Also area spells (Frost ring the best) are good to help them when surrounded. [It might be even reasonable to use fireballs, if their opponents are weaker - especially if the fireball could win the battle - because if you'd spare the dendroids from your own flame, enemy might hit them with his own spell.]

Heroes:
Rangers are a mixed group. There are nice picks like Kyrre the Logistics expert, Thorgrim with magic resistance and 5% bonus to it, and on the other hand Ryland (Dendroids) and Ufretin (Dwarves) that would make good castle defenders. A secondary pick is Jenova (+350 gold).
From druids, I recommend Aeris(Pegasi) and Alagar(Ice Bolt, has Sorcery). Also Elleshar with Intelligence may come handy (esp. for castle defenses). Others seem quite useless to me under common conditions.

Skills important for the troops and strategy:
Given so fast units, Tactics may be the best pick for you - your centaurs, pegasi and unicorns will be able to pick most of enemy units for targets. With Expert Haste, you will be able to attack slower enemies even with Dendroids and Dwarves.
Since you have only one flyer (except dragons) and one shooter, you should get Ballistics to let your Unicorns and Centaurs make some justice, especially when you expect many castle sieges.

Unit	A	D	HP	Dmg	Sp	$$	AdjD	Dm/g	grow	weekD
Centaur captains	6	3	10	2-3	8	90	2.30	2.56	28	64
Battle Dwarves	7	7	20	2-4	5	150	2.82	1.88	20	56
Grand Elves	9	9	15	3-5	7	225	3.92	1.74	14	55
Silver Pegasi	9	10	30	5-9	12	275	6.86	2.49	10	69
Dendroid Soldiers	9	12	65	10-14	4	425	11.76	2.77	9	106
War Unicorns	15	14	110	18-22	9	950	25	2.63	4	100
Gold Dragons	27	27	250	40-50	16	4000	83.25	2.08	2	167