MMA has always been about becoming proficient in a solid base skill set ( grappling, striking, ground fighting, whatever) and learning enough of the rest to counter it and impose YOUR skill set.
People learned very quickly that if they have been striking for 10 years that no amount of grappling training was going to allow them to beat a grappler that had been grappling for 10 years at his own game, it's just not gonna happen.
What they did find out is that they could learn enough to do enough to keep the fight in the conditions that favoured THEIR skill set.
Psalms 144:1
Praise be my Lord my Rock,
He trains my hands for war, my fingers for battle !