He doesn't have to drain Alan of the Starheart in its entirety - which I doubt would happen - to use Mjolnir to nullify a great deal of Alan's offensive options.
Thor has been put down with energy/force before. And Alan has more than enough of that to take him out. Hell, didn't Spectrum (Marvel's GL) do well against Thor in their initial meeting?
Yes, energy attacks have taken down Thor before. He also has a strong history of energy defenses via spinning Mjolnir, absorbing it, or sending it back at its attacker with anywhere from times ten to times hundred power.
Spectrum did do okay and managed to temporarily disarm Mjolnir from Thor, iirc. Unfortunately, such a method delays Thor until Thor's will causes Mjolnir to free itself from whatever trap it's in. Just recently, Thor willed Mjolnir from Earth to another dimension in moments.
In any case, there's more evidence suggesting Thor does well against energy manipulators than there is against it. Definitely enough feats to suggest that Alan "stomping" Thor is out of the question.
I always thought this the oddest of tactics. Superimposing anger on one's opponent in order to feel superior or laugh at some sort of perceived victory. At best, he's actually mad, and the acknowledgement of it does nothing to increase it, only point it out. So, best case scenario, it's neutral. Worst case, it's self-delusion for the sake of petty smugness.
I get that you don't like Galan, but really, are you not above this?