Lets not overrate Lesnar that much. He fucking sucked as a fighter for the most part of his MMA career. He got killed by Cain. Looked like he was about to cry from the beating he took. He got murdered by Overeem. I mean, he really got the shit beat out of him by Overeem. Then, he got killed by Shane Carwin for the entire round, before locking in a submission to win the match. He tapped out to Frank Mir 3 minutes into the first round.
All he did was use his size to win, but then when he started fighting guys more his size, he showed that he is not some tough guy. His standup sucked, his ground game was decent, but his massive size helped a lot.
Its just the stupid WWE fans that think Lesnar is god because he beat a 45 year old man, who he outweighs by 50 pounds in order to win the UFC title.
Lesnar was certainly never the best in the world but to say that anyone that's ever captured a major title in MMA, or just beat a top 10 fighter, "fucking sucked as a fighter" is downright pathetic. It also sounds like you're suggesting that the only people Overeem and Cain can beat easily are people that really sucks, which seems very insulting.
And if you only think he used his size to win then you don't understand the techniques of MMA. Of course he was helped by being big and unusually athletic for that size, but that's not nearly enough to beat anyone at that level. His wrestling was good and his BJJ top game developed really well and how he managed to completely shut down Mir's hips in the second fight was very impressive for such a new guy.
So while Lesnar certainly wasn't god it's just as silly to downplay Couture as just a smaller, older man.
I've trained in martial arts for 20 years and have had some international competition success but I couldn't step into the UFC and do what he did. Therefor I'm impressed by what he managed to do with so little time.