i myself have thought about the armor problem for quite some tim now. and i found a solution, even though it's not that smooth, i think it's the easiest possbile without the massvie use of hardcode jass
//do this for every hero
create a copy of him (including all hero abilities, etc)
switch the armortype of each copy so that there is one hero for each armortype
//do this for each armortype and hero
create an ability that allows you to morph from a hero (e.g. 'normal' armor) to every other armortype and from every other type to this one
now you can add the morph ability (i would suggest bearform with 'permanent') to the hero, order it to morph and volá you got the armortype you want.
if the current type isn't the one of your 'normal'-hero than morph to the normal hero and then morph on to the armortype you want.
i know this is quite some work doing so many heroes and abilities for each hero you want to ahve, but unless you have found a way to edit _all_ atributes of any given object - thats the only way i can think of right now.
hope it shows you the way of doing ot - i would love seeing it done (even though i'll not do it that way if i have more than one or maybe two herotype/s...)
- Raszul