III.10 comes out a lot better here, and III.8 looks like the big wimp. I suppose you can look at this list as "the hardest league to avoid relegation in" ranking. A rough calculation compared to Simon's fine tuned formula, but some more fuel for debating.
You can, but of course you'd be wrong. ;)
If you wanted to come up with something to evaluate the difficulty of avoiding relegation, you'd have to have something that weights most heavily the bottom three teams in each conference - if the top five on each side are elite and the bottom three are poor, avoiding relegation should be a piece of cake. Likewise, if all sixteen teams in a league are good, even if few are elite, that's a league where good teams get relegated. Naturally, if the calculation were instead the hardest league to promote out of, those two hypothetical leagues would be flipped.