Hiya!
Probably gonna get roasted for this...
I'd call it a "War-Speaker". I'd also allude to virtually all of the 'abilities' that let the War-Speaker force others to move or act in some way as being "magical in nature" (kind of like a Clerics Turn Undead, for example).
If presented like that, I could (as well as my players...if we ever get to meet up again and play!

Stupid viruses...!) get behind the concept.
But, as it stands, the "Warlord" being a guy who "knows battle so well he can force an opponent to do something stupid...even if that opponent is thinking 'Uh, no...that would be stupid...I'm going to stay here and keep doing what I was doing' (re: forcing a Player to make his character do something they don't want him to do)...that I can't get behind. It annoys me to no end.
But...make it "magic", and now we're ok. Now I can RP the aftermath as "He was a War-Speaker! Their devilish tongue can beguile the mind into making stupid mistakes in battle!", or some other such 'not my fault' excuse.
The only way "around" that would be to allow some sort of "consequences" result; almost like a 'reverse-saving throw'. So the Warlord would use a 'power' that forces the PC to move 5' in some direction of the Warlords choosing. With the 'drawback' being that if the Player STILL chooses to stay there and NOT move the 5' in the direction the WL wanted him to...then the PC suffers some bad thing; AoO's from anyone with missile weapons, a bonus to hit and damage for the next attack from the WL or his friends/side/minions, or automatically drops initiative to the bottom of the heap, etc.
The RP'ing afterward could make sense then: "I KNEW he was trying to get me to move a bit back...but I didn't know why! I figured he might be trying to set me up for some AoE spell from his wizard or something. Huh. Turns out I probably should have just stepped back...I didn't see the spearman to my side before his spear tip was tickling my liver!".
^_^
Paul L. Mingz