health and ap are pretty simple, I tried tracking endurance down and got a few possibilities but none seemed to work.
I use cheat engine to handle money and AP. I tend not to need health. The big problem is the addresses change each time the game loads, ranges I've seen so far are 0x03 to 0x05, which is a rather large chunk of memory! Lucky AP is easy to track manually but I can see there being problems doing with a trainer unless there is a marker or something that makes the merc stats standout! TBH it all kinda points to a memory leak in game but we'll have to wait and see.
PS. cheat engine.. start a map, 'new search' for AP of character xxx, crouch, 'next search' for new AP, stand, 'next search' for new AP. Once it's narrowed down to 1, double click to save it, add a description and change the value, do it for the next character if you like.
Like some other people, my trainer also crashes whenever I start a new game or load a game, regardless if I start the trainer before or after the game itself. I have the english version, and I have the game version the trainer is supposed to support.