I think Rory would beat him handily. Askren's shot isn't explosive, he more or less has to get close and drag you down. I think Rory would use the jab and kicks to easily fend him off. Askren got deep on Hieron a few times and was easily stuffed.
The guys Askren has fought aren't the best off their back either. UFC top 10s know to get to their feet much better than a Lima or the Russian the other night. And guys like Maia, Condit, Diaz have a guard that he hasn't seen in MMA as well.
Askren is brilliant on top. But his TD game is overrated by people just because of his world credentials. There have been a lot of one-dimensional world class wrestlers that never made it to the top. Effective vs. average talent, but never making it to the top.
Other than his top control, I'm not sure what people see in him. I guess his cardio is real good as well. If he could develop any sort of sub game from top he would be deadly.
Hieron stuffed one takedown if I remember correctly, and Ellenberger took Rory down with ease. I agree that Askren has some pretty slow shots but he has the strength and technique to get them on a guy like Rory who honestly is just avg at wrestling. His grappling is amazing, and he has good enough sub defense that guys like Condit, Diaz would not trouble him too much.