I don't see much ganging by Ahtieli, and I have seen him fight quite a lot.

I did witness/join a big ganging involving him the other day, but as one of those involved in the ganging (or at least, I would have been had I not failed my wither commune and seen the enemy fall before I came out of lag from it), I can say that that was not Ahtieli's fault.

Pelrin hit centurions, and I and another recalled from ranking to defend when we heard them yell, not realising that other people were doing the same. When we got there, Ahtieli and another were already fighting Pelrin. So that will show as a 4 on 1 gang, but Ahtieli did not in any way cause it.

Other than that, I don't think I've seen him have the advantage of numbers, unless you count the many many undead.