This is actually the case with DRG too. Had a bunch of friends on Game Pass play it then later another bunch wanted in on Steam. I bought it on both platforms (before I subbed to GP) and they’re both separate eco-systems which is annoying.
On Fireteam: we tried doing a campaign on Extreme with our fresh-out-of-Intense-fully-maxed-out marines and it felt absurdly difficult. I think we managed to do the first level and it was thrilling, screaming-into-the-headset tense stuff. Everything we play these games for! But the second level we never got past a certain corridor no matter what strategy we used. Standard xenos just ate bullets. We came to the conclusion that without certain classes, Extreme was nigh on impossible.
Our original Intense difficulty class combo was demo (me), tech (friend A) and phalanx (friend B). After banging our heads on Extreme we went into horde mode (Intense) to level some other classes up: gunner (me), tech (friend A) and demo (friend B). We once got to wave 20 and could comfortably get to 10. When we went back to the campaign on Extreme we still got our asses kicked, pal. We even brought two demos(!!) at one point (mine maxed out). We couldn’t work out whether it was the tech not bringing the firepower, the gunner and demo not being high level enough, us not being good enough or a combination of the above. It didn’t feel like a ‘git gud’ issue; it felt bonkers, like we were nowhere near powerful enough to tackle that difficulty. And there’s Insane above it!! We wished there were a collection of horde mode maps to play because we loved jumping into that mode but got tired of the one map. To have a whole game’s worth of areas but only one horde mode map seems crazy to me.
We’re all really looking forward to the new DLC though. Hopefully that will give us the levelling leg-up we need.