RTW and BI: Army composition vs. the AI... and Shield Wall ability (BI)

[piranha45]

in your experiences in the campaign mode, is it worthwhile to have a heterogeneous army? I've played through vanilla RTW in 3 campaigns and never felt a need to build anything other than the best available infantry unit, and use extra generals as cavalry. Except when i played Gauls; I massed Forresters instead of melee fighters. I'm under the assumption that having mostly-infantry with some accompanying skirmishers/archers negates itself due to friendly fire, which makes all the ranged units practically obsolete when fighting the AI (unless the faction has super-quality ranged units like Forresters, who can form a perfectly viable army without any melee infantry at all). What do you guys think?

I've now started a Frank campaign on VH/VH, and alot of my units have the Shield Wall ability. I've noticed the units move slower when it is activated; are there any other drawbacks to using this? Does it raise Defense or Attack or what? Is it smart to ALWAYS have your units in Shield Wall formation when they're engaging the enemy, or is it better to only have them use it when they're in Guard mode/defending?

[Selifator]

The sort of army I use varies with the faction and available resources I have in the game.
Shieldwall gives defence bonus against front and (I think) side attacks, but like the phalanx is vulnerable from the rear.
This works fantastic against cavalry charges and also against infantry.
Drawbacks: slow movement, smaller frontage thus units aren't quite as effective in shielding other units (archers etc), vulnerable from the rear to charges and missile attacks, vulnerable to swift attacks.
It is better to have them in shield wall when defending, and having them in guard mode. When you charge, your shieldwall will break up and leave you more vulnerable then when you are standing still.
When you are standing still and the enemy charges they lose a good amount of charge bonus. Thus cavalry without maces is vulnerable since they can't easily break your formation from the front.

[Ephialtes The Dog]

Shieldwall is basically like a phalanx that can run and has shorter spears. As for army composition, I like to make my armies as historical as possible instead of just spamming Urbans and Praetorians. It adds to the fun in my opinion.

[Selifator]

And to me, a full army of heavy infantry using shieldwall looks a hell of a lot better than a phalanx line.

[Hader]

Moved to battle planning.