I noticed when I went through the guide to MTW there is very little on battle tactics and strategy. I know many battles are different in some sense, but I thought this might be an area that some people could share on. Of course variables are;

defending or attacking

the make up of your army (type, valor, morale, shields, etc.)

the make up of the enemy army (see above)

even numbers or is one side out-numbered

the starting points that you have a choice of

terrain (bridges, hills, forests, dunes, etc.)

your generals star level versus enemies'

I noticed bridge battles, sieges, and use of HAs are covered, but I don't see much beyond that. Too daunting a task ?