To be honest the current Rak is amazing due to two things, the 270MP and the stealth mechanic. The use of 2 Raks with stealth definitely gives the player more option for strategic ambushes. Also, I dont think Raks have too much problem with penetration from by experience. Yes, raks struggle with Churchill and heavy tanks but you should be able to have some armor available.
Also, the stealth mechanic is EXTREMELY useful for sneaking up on Priest and Kats in large modes.
Rak is mostly extremely useful in sneaking. Rak definitely has good enough penetration.
In terms of supporting however, not so much. Supporting lights in general is just terrible.
For 270 manpower, I would pick every time over the USF AT gun since a way better support weapon. Mostly due to the fact it is far superior against both lights and mediums. That is why I prefer it.