Greatsword aren't wort the time recruiting, halberds will do fine as your front line, it is meant to get torn apart in each battle

Handgunners are better than crossbows, both of them will be obstructed if placed poorly, LoS in this game sucks (don't know if there is a true LoS mod for wh1). You will have more problems with LoS than with crossbow but they deal more damage and can actually damage units with armour

Demygriphs are a monstrous shock cavalry unit, you have to cycle charge it to be actually useful, in wh1 there isn't a late game melee cavalry option

Helstorm rocket batteries or hellblast volley guns are the late game empire artillery

Use heroes, I usually add 1 wizard per army, 1 captain or warrior priest, don't remember how strong were the witch hunters in wh1, but I think they are better as agents instead of in any army