^This. With shin splints I'm already barley able to pivot.
And as for Brock with his disease. You said "he changed after the Carwin fight" (@ rabakill). The Carwin fight could have been easily stopped, making it no different from the Cain fight. Lesnar didnt do anything different in either fights. He lay fetal and took a beating. One ref opted to end it, one gave him the chance to go on. Luckily for Lesnar, Carwin half died in the first and he got the submission, but there was virtually no difference between the first rounds.
I've got loads of respect for Lesnar and think he did something different and was highly successful with it, but when he faught proper strikers he crumbled every time.