He is one of the greatest collegiate wrestlers of all time. He holds wins over guys who became NCCA greats themselves. NCAA season pins record, 3rd NCAA all time pins, one of 2 guys to be awarded the Dan Hodge trophy twice. Olympic level wrestler (he was a folkstyle wrestler competing in freestyle). 4 time All American. Askren did all this being a tall, lanky wrestler with an unorthodox style.
...oh yeah I think he won a pan ams too, he has solid submission grappling on top of some of the best folkstyle wrestling.
Anybody who follows collegiate wrestler knows how insane Askren was and how good he really is. He doesn't sit in guard and blanket guys, he is always moving, always transitioning. He has some of the best rides(wrestling move) in mma.
Credential wise he is in the top 5 wrestler to ever start MMA.