Trying to take advantage of a randomized system is just asinine. You would really have to put a lot of effort into doing this. The reason why new players are quitting so fast is because of the injury system being so rediculously luck based as is. Ap cost not lowering... Fine whatever you say, but any system can be manipulated. Like I said trying to do that with a random system is borderline full retard. No one wants to get injured, and if you made the beneficial ones come with risk then that makes sense to me.
Example: PoB Is injured, -1 will (vulnerable to fear) you have to wait 3 days for this guy to see if is heals naturally or you get a negative or positive outcome. 50% of people will heal it right away, 25% will buy a new one. 10% will heal and be fine. Of those getting negatives or positives, we will all know what they went through to get it. It's earned positive or negative.
It should be a 2 way slope though. If no ap reduction then no ap increases for positive effects. Mercenaries that have been around for a long time will be different from noob mercs.