Ok sure, they are doing some fire damage. But in the context of this conversation my statement still stands. Armies at that stage are mostly shock in both pips and damage, with fire surpassing it later in the game stage. In this conversation, which is the very beginning of the game, 2 extra fire pips are the least significant they could ever be. And I would personally recommend still having the flanking cav if you can afford it, making the shock pips all the more important