Hm? Ambush camo on 42s is bugged. I've seen it a few times in this patch, unless it got very recently ninjaed. You can see the unit, you can't shoot at it though. IIRC a guy called Arthurkrupp uses them alot, he is a solid OH player. Still, ambush camo is in nonviable doctrines. No amount of ambush camo is gonna protect you from an IS-2...
Actually, you would be suprised. Jaeger infantry is an amazingly underused doctrine. The mg42 + camo is great, and when you upgrade your 3-4 grens with g43s, you can murder infantry that get caught in your suppression field. You need to rely on Paks for AT, but thats not really a problem nowadays with the new TWP.
Additionally, a PGREN with shrecks behind your paks will deal large amounts of alpha damage to enemy armor. To top off the power of the doctrine, you get the borderline OP Stuka CAS loitering strafe to murder enemy vehicles and support teams. It can easily shave quite a bit of health from an IS2 with engine damage or pathing issues.