Is the Trample bottom action considered an "attack action" for purposes of War Hammer, to stun every enemy that was attacked with this ability?
I think yes, but I'd rather have feedback about it.
Yes, of course. My favorite combo with the Brute is Trample + War Hammer + Boots of Striding + Power Potion; run through 5 enemies, attack them all for 3, and then stun them all. Paired with Balanced Measure also gives another 6 attack at the end.