Seriously? Damn didn't even think to check that, it seemed innocuous enough. Whelp, back to the drawing board, given how garbage myrmidarch is...
Outside of a PFS context though, what's your opinion on going any further into gunslinger otherwise for multi-classing? I understand that it's a bad idea to take away from your spell progression, but gunslinger has the advantage of being able to go up to level 3 with the musket master archetype so that the gun can be reloaded as a move action, and of course five levels gets you gun training. (Not a ton of point going further than that though with multi-classing.) How viable is a magus once you've sacrificed that many levels though?