Thurman ain't got quit in him, just because he's a hippie, people mistake that for him being soft, I think his war with Porter and domination of Danny Garcia should have been enough to dispel that myth. Keith hands down has the best resume at WW, and is being written off far too easily, if he can get anywhere close to the form of the Garcia match, he's still very much a force to be reckoned with, and can beat both of them.
Lol I like your optimism. I think Garcia will do better than some expect vs Spence but I can't see him winning. Gotta live Garcia's ambition though, I'll be rooting for him to shock the world.
I would say Spence. Though I know Crawford is also special and confident in himself. Thurman is very good like Danny Garcia and Shawn Porter just not special in my opinion.
Mikey Garcia is a great fighter with good skills as well but he would have been better off facing Lomachenko instead of Spence Jr.
Thurman has a solid resume as do Garcia, Porter, Spence and Crawford. However Erroll Spence took the title of Kell Brook who was the best at 147 and made him quit in his hometown in a great fight. That tells you all you need to know about Spence Jr.
If none of the 4 belt holders fought each other its gonna come down to whoever has the best competition.
I just have not been impressed with Thurman for quite a while now. My guess is Spence takes this(but definitely can't discount Garcia)
Sorry to be the bearer of bad news but the answer is.... Spence... And.... Crawford. These guys aren't fighting anytime soon, sadly.