Silent-
Go back and look at what yepe said.
What you are saying should happen to otherwise equal but different capacity packs, but it did not.
IR is a factor independent of capacity (just like you said) that would account for different drains on paralleled packs.

Reading yepe again, the fact is he's not paralleling two packs as we assumed, but using two different regulators with their outputs paralleled.
Probably Portland really has it right.