I'm not sure ngIq maH is quite correct for each of us individually in this case. So far in canon, ngIq seems to have only been used with singular nouns. To me, if we applied the examples strictly, ngIq maH would mean something like each group-of-us individually, as if there were multiple groups of "us" ("us-es") and we were considering each group of "us" one by one. In that one TNG episode that ends with a couple hundred Enterprises from parallel universes appearing, each with their own Picards and Rikers and Worfs and so on, it might make sense for the Enterprise crew to refer to multiple groups of "us" like that. On the other hand, there are still some questions about how to talk about things like "each of us" or "all of you" and so on. Maybe with a plural noun, ngIq can mean "each of the things that make up the plurality" rather than "each of the plural groups", so ngIq maH would mean what it's supposed to mean.

Whatever ngIq maH means, and whether it's the correct way to write each of us, maH would still be the head noun of the phrase, so it would make sense to have a ma- prefix on the verb.

(Incidentally, was there ever any traction on adding grammar question requests to the qep'a' chabal tetlhmey, like we have with vocabulary?)