[halfzware]

I've sorta played around with the same idea myself. The big problem I think is that it would actually end up taking away from the diversity in the game. If you can fully customize units, then almost inevitably you can find 'optimal solutions' that is: equipment combinations that are with very few exception optimal.

Instead you're forced to make controlled trade offs, none of the units are optimal, each has strengths and weaknesses. For example, flagellents have almost no armor, and a flail - but they're sacred and capable of amazing damage especially with a fire bless. They cost something like 15 gold. So they rock, but they have no armor so they're vulnerable to missile fire and big area damage spells. If you could configure them yourself then you could compensate for their weakness by example giving them shields. This contrary to common sense takes away from the diversity and trade-offs in the game.

The thing that dominions DOES do that allows you to sort of achieve what you're looking for is give some impressive spell effects that allow you to change how units perform. Although I'm not as familiar with spell effects as most people - I know there is a spell that stops missile weapons from being usable, a bunch of spells that give armor bonuses, and other protections. In this way you can (with attention to detail) get some very customized performance from your units.