If you see a Pony/FM2 coming in for the head on, take the shot. If they are willing to take the head on, then they are either foolish, realize that it is only a game, or Enker.
or...
you can use the enemy's poor choice of going for the head on attack as their merge to do some very basic ACM (*cough* break turn) and shoot said enemy down in 1-2 moves. I supose YOU don't mind getting damaged but me? I don't mind waiting the extra 3-5 seconds to kill them. (not to mention never allowing them a free shot at me)
WHY would you purposefully give the enemy that free shot on you? Sure the 4x20mm of the niki should "win" but at what cost? Even if you don't die right off from being dumb and HO'n the nme is STILL going to land rounds on you and damage ya' ensuring that your NEXT opponent kills you. (so in my mind, you died to the HO)
With a Niki you have too many options to just "give up" and be "stupid" and fly around trying to HO the nme. I almost never ho. I almost never get ho'd (though they try). I manage to keep (usually) over a 10 kill to death in a niki tour in, tour out w/o ever resorting to a head on.
Enker might be "ok" with one kill (or less) per sortie but I for sure am not. Every time I take off I plan on landing with kills. Givin' my opponents free shots on me is not very conducive to racking up kills and landing them successfully.
Clonk, it is as I said at the very beginning, almost nobody in the game has a clue how to fly the Niki (for example: Enker, Chewiex and Belial). When I say almost nobody, I mean it. I can only think of 1/2 dozen player over the past 6-7years who really understood and knew how to fly the Niki and had mastered even a few of the Nikis many tricks.