Some questions about armies

[wisecat]

Could someone please help me with this armies questions:
1. What are they good for anyway? I do not u-stand benefits, but there is at least one detriment- putting units into armies which do not have multiple attack capability decreases your number of attacks per turn
2. Do units within armies progress in rank?
3. If I have an army build of elite units - will leaders appear after army winning an attack?
4. If there is an army composed of civ-specific units - will its wictory trigger a Golden Age?
I will appreciate all help and comments

[Gramphos]

The armies are good as the hit points of all onits in the army is added. That makes it harder to kill.

I've never seen any promotions in armies.

[benjdm]

2. I have seen members of armies advance in rank.

Don't know about the others, though I suspect 4->yes and 3 ->no