I can't speak for 2v2 as I don't play it. You'll have to ask the 1v1 experts what they think. I see it virtually every match involving USF in 3v3 to the point I assume they will use it. Usually by high ranked players, ie: ppl you can't just outplay 2x to defeat. One person accused me of maphacking because I saw his AT guns coming via Kubel vet I but was perfectly fine with his triple Paths seeing 70+% of my army for that match.
Well I can speak for 2vs2 on your behalf consider my team is level 17 with 7 replays on tightrope channel so I myself got some exp in high level 2vs2.
Usually my Axis team see this pattern:
1. Pathfinder x2 + Rifleman x1 OR Pathfinder x3
2. .50cal from Tier 2 OR airdrop for Pathfinder to pick up
3. Flak Halftrack
4. AT gun x1 or x2 + BAR upgrade for Pathfinder
5. M8 x2 or x3
6. M36 Jackson
And this is pure cancer build: with Panthfinder ready at 0CP, my Ostheer MG42 is useless because they already spot it before I can spot pathfinder and later in the game as Ostheer I would just bleed out from the M8 spam.
Tbh whenever my team play 2vs2 and I see (and feel) that the USF gonna play Pathfinder spam I'm just gonna switch side with my OKW mate so he can use JLI to counter this (They come out at 1CP, can detect camo unit + also got 50 sight + can snip the shit out of them). My mate usually mix JLI with Ober in order to kill this Pathfinder quickly.
So yeah, either my mate switch side and deal with USF or I say fork it and play a name match. As Ostheer player and at my current level, I'm not capable of dealing with this atm IF my enemies are good at abuse Pathfdiner spam in 2vs2.