FSJ are pretty ridiculous. You can charge them into melee against shock troops and win more than half the time- due likely to their insane damage on the move. Not only that but the volume of fire from the FG42s rip any vehicle short of a light tank to shreds simply through raw dps. Honestly, losing the faust wasnt even a huge nerf because without it FSJ still hardcounter most light vehicles.
Let's be real, if paratroopers only had 5 men like rangers they would be woefully underpowered. You yourself mentioned that rangers get stomped by FSJ and per model paratroopers are actually WEAKER than rangers. Paras are powerful sure, but not as cost effective as rangers amd certainly not as cost effective as FSJ.
Yeah Fallschrimjagers are second only to Paratroopers, they really should be a CP3 unit, and I haven't used Rangers on a long time but LOL if they're still a 10 pop unit. Not worth it at all.