Ignacio is a great choice and he's certainly up there.
Nearly all of his best fighters Zaragoza to Lopez to Marquez had common attributes which demonstrated the system he has nurtured to bring these guys to the top.

Futch is an obvious selection and very deserving of his reputation. He may be the best.
Charley Goldman has to be appreciated for his abilities as an alchemist.
I think Arcel was exceptional.
Goody Peteronelli did a great job with Collins to concrete his work with Hagler. Even Simms was a dman good fighter.