NO no, I didn't want to make you look like a fool, you have your point of view, I have mine.
So, Dean, grow out the tomatillos, observe, try, also observe other plants (if, for example, you already have experiences with pepper crosses while they're at a distance of 20 ft, you could be fearing tomatillos will certainly cross). Or.. if you really want to make sure (and have the time to do it), put an some isolation covers over each of the varieties (one variety = one net), open up the net of the first variety the first day,close it again in the evening, open the net of the second variety the second day , close it again,...