Quoting Lafate's Class and Army Guide: http://harem-battle.club/millennium-...-1-2015-a.html
Basic Team Composition:
Now, I know why most of you are here. You are new to the game, and wish to know how to make the best of the starting units given to you. However, some of you may just be here for a list. Not actually caring about what I have to say here. So in interest of not wasting your time here is your list.
1: Bandit or Rogue
2: Heavy Armors
At this point you will have briefly stepped into completing your basic team composition. the rest is simply adding on 1~2 units of every class to cover more ground and cater to the needs for the current or next event. The basic units to level at the start are what people call the 'H-A-T' core team (Healer-Archer-Tank). If you deviate from this point for any daily missions or events, you will slow down your leveling and may end up slightly lacking for the next event, so do so at your own risk and judgment.
If you carry on in this manner, you'll eventually reach a point where you'll be experienced enough to know what units are necessary, what units to prioritize and stuff like that if you ever start an alt. As a reference point, me and Tenhou both managed to clear Golden Armor H with 1.5 weeks of gameplay, and Crystal Keeper H with 2 weeks, and get an almost perfect unit from a star rush event in DMM (some degree of luck was involved) after 1 month of gameplay.
(Note: DMM = the japanese aigis, also the original aigis that nutaku's aigis is translated from)
Whatever units you are lacking or any weak areas in your team can be eventually supplemented with event units in the long run
, but you'll eventually want 2 soldiers, 3 archers, 3 healers, 2 tanks, 2 mages, 2 witches and 4 duelists including at least 1 valk and 1 bandit. You can also override the above priority leveling units with units of higher rarity. the only exception is Alissa: you probably want a low cost healer for emergency needs.
(Note: Bolded line includes any golds/silvers you accidentally used up. Commitment to this game is the key here)