At this point, I'm mostly in agreement with you. Really after all of the digging, and the mulling, it started to feel like (considering 3 distinct and disparate ages) that too high a level of realism isn't achievable without huge overhauls in the recruitables, including creating many new types of armor, tweaking gold costs, blah blah, tons of stuff way beyond the intended scope of the mod.
So to sum up - It really seems like ultimately the actual Encumbrance difference between Bronze and Iron is minimal, and too small to simulate in Dominions terms (Bronze won't be 33% or 50% more Encumbering), and because of the small numbers, probably wouldn't be noticeable until Steel armors, if at all. Likewise, differences in Protective ability were not overly profound, other than if we say that all Bronze is cost, and all Iron is wrought (for sake of game), in which case the wrought items have greater density, and then of course there is a very noticeable jump again, to Steel.
Then it's just a matter of looking at the various armors, and trying to determine "does the actual design of a Hoplite Breastplate differ significantly enough in design properties from an Iron Breastplate to justify a change in values". I guess at a certain point, you allow some things to have higher or lower numbers just because they have a different name, and the intent is to have different capabilities of the units.
Grrr, I'm glad I joined into this conversation, but I am also sad.
I'd imagine you feel the same way, by now.
