TC arty is fine. That is the only thing it has going for it besides the command vehicle. The rest of the abilities including the engineer scavengers are pretty weak because they can't be upgraded to heavy anvil engineers or anything.
It's not a bad doctrine, but I wish they toned down the muni cost for the forward observation post. It's extremely expensive to use effectively.
The support drop for 150 muni is also pretty nice. You get ~600 manpower of support units + healing + all units on the map move a lot quicker for a decent duration. I found it nice for giving teammates (especially soviets) some extra oomph in the mid game.
The salvage engineers work great as repair drones and being able to supplement income with wrecks is very useful.