You do realize that guys like Anderson Silva and Nog are more training partners than coaches right? Brock has some of the best coaches that money can buy. Don't let big named fighter fool you into thinking they are great coaches.
Not at all. Dos Santos will bring in the Blackhouse trainers Luiz Dorea who is one of the best boxing coaches in MMA and he has said he has had Big Nog, lil Nog and Damien Maia rolling with his guys alongside Jorge Guimaraes.
He has Rogerio Camoes on conditioning too which is no bad thing.
Lesnar has decent coaches but most of them are wrestling based as expected, only Rodrigo Medeiros is a genuine BJJ guy and Peter Welch is a decent boxing coach but no better than Luiz Dorea.