IMHO I don't see the point discussing about negative sizes and costs for shot or gear for such a relatively tiny enlargement size.
Any of those machines will give more than fine results, and ALL have serious cons depending the user. Personally I don't like the 645 format, and even less the vertical frame of the bronica, but it's fine if it's intended for portraiture. Now I own a 7II and I'm more than happy with it, but only because it suits my preferences better.
I don't think that high price should be an issue when someone already is considering a specific camera, but if it is, a finely cla'ed Koni-Omega will give the 6x7 size with fine lenses and a RF. Not as convenient but sharp as any of the stated, but RF, and yes, probably you can tell any difference in the final print, but not enough difference to justify the bronica
Rent both if possible, then decide. Technically for a 16x20 you can't go wrong one way or another.