He doesn't pack the same punch? I think he's more powerful puncher then Cain. Cain punched Antonio Silva like 200 times, Cormier decimated him.
I think Cormier picks his shots better than Cain does also. Cain just dumps an avalanche of strikes on his opponents, where Cormier sets up shots and seems more calculated in his attack.
he seems to have the faster hands and he seems to throw with more confidence then cain does. but i think he hurts people because they don't expect his punches/don't see them coming more than his actual power. bigfoot was pretty much out when he hit the floor, and he remains the only legit ko on dc's record (this staring guy isn't legit and got stopped because of his helplessness rather than dc's power numbing him).
while cain tends to out-volume his opponents standing, i think most of both their striking success stems from the very iminent threat of a takedown. while i do not think of daniel as a particularly bad striker, he didn't do anything to overwhelm me either:
bigfoot most probably prepared for a one-dimensional wrestler, and got rocked by lesser strikers like mike kyle before; he's also kind of slow. that plus low hands that expect a takedown goes straight towards being ko'ed.
barnett isn't exactly a good striker either, also he broke his hand early in the fight.
dc tends to have his head way up in the air while dropping his hands during his attacks; if keeping-distance-mir shows up (who will carry an 8' reach advantage into the fight) and manages to move wisely and attack from angles, he is definately capable to hurt him standing.
while i think that mir is by far the most athletic, most versatile and most dangerous opponent dc has faced, i still would bet on cormier if forced to...