Yair's last 2 fights...IDK man. He looked good for stretches vs Caceras (I was actually very impressed by his gas tank in that fight--his style would lend itself to slowing down a lot and he really didn't) but he didn't look amazing imo against a good but not great opponent.
And BJ Penn...jeez he really is just a shell of a fighter. He was done years ago and then the layoff too. I mean, yes Yair looked good and did what he should have so not saying you can hold anything against him there, but c'mon.
Frankie (as was pointed out) has only lost two competitive decisions to Jose freaking Aldo in the last FIVE YEARS. Look at the guys he's beating too (and making it look easy for the most part). Brutalized Cub. knocked Mendes out in rd 1, bested Stephens (which granted was competitive but Stephens is a huge FW with big power and a guy who seems to have made big leaps over the second half of his career).
Edgar has been fighting (and for the most part beating) the top of the LW and FW divisions for like 8 years now. Unless you think he's on some big decline (and he didn't look like it vs Stephens imo) then not sure how you can't make Frankie a moderate favorite. His cardio, boxing, wrestling are all top level. Yair will have the advantage in being the more versatile striker and probably will have a small speed edge, but that's about it imo.