My understanding was that Infiltrators were NOT meant to be modeled after Ninja.
Half the problem, in my opinion, is in the name. When I see Infiltrator I think of using stealth to get where I should not be. Stealth has largely been removed from the class. Sure, in theory, the Infiltrator is being stealthy as he goes from his camp/lodging within a region to the location of his target withing that same region and back. The problem is that it really does not sound much more stealthy than when a troop loots the tax office. In both cases you have to be the region and everyone can see you are.
I personally love the idea of adventurers being able to pick up some of the cloak and dagger pieces from the old Infiltrator class. As a subclass perhaps. One argument against thee old Infiltrator class was that no noble would ever act in such a way. An Adventurer would I think.
I also like the idea of the spymaster focus for the noble. I have a hard time imagining the mechanics but it sure sounds cool!
