I will be fair and say that the numbers do have some basis in prior rules. Some of them. 29 is obviously a base of 15 plus the entire Constitution score, 14 is just the Constitution score or 10+the weird ability-score-minus-ten modifier they may be toying with, 12 is the standard d10+2 Con mod, 7 is either half the Con score or 5 plus the 3.5 modifier, and 6 is...actually, why is this even an option? Is it really that far from 7?
But the mere fact that they are doing this means they don't have a system for this in mind, which means that combat in general is smoke and mirrors right now and also strongly hints that they don't know what's going on with ability scores either. I've seen some weird numbers from playtesting and it sounds like what they're doing is both convoluted in weird ways and plays hob with probability.
I strongly suspect that the playtesting they did was largely do-what-feels-right DMing which they will attempt to reconcile with the results from these polls into a workable game system. So, you know, we'll see how that turns out.