I don't think it takes that much to exercise imagination in this regard. Rand's defeated Rahvin by confronting him directly, and Rahvin's modus operandi and intelligence mirror Graendals pretty well.

Anyway, frankly speaking, I don't think that your failure to imagine any other possibility aside from massive use of balefire as a solution to this problem would prevent you from explaining why the thousands of ways Rand could have done this differently would not have worked.

My response is that Rand was a psycho and verging on becoming the Dark One's pawn in TGS and that scene especially.

Honestly, sometimes I think there are fans that would have preferred Rand balefired Nynaeve, destroyed the Borderland armies and perhaps Far Madding and then balefired the Seanchan with the amount of glee some of the more disturbing scenes in TGS produced.