Yea, that is what I was noticing as I was messing around it just seemed to further reinforce what I would experience in game when ever I tried to use Rangers/Para Thompsons. That is part of the reason I was surprised to AssG being able to beat Shocks/Rangers with vet but I guess that shows the strength of mix-model squads with single LMG squads being the most extreme example.
Part of the reason I specifically used Grens was the issue numbers can't really explain. As all LMG have focus fire it really hurts scaling of short range units, especially late ones like Rangers. Having good RA is nice but since the damage gets focused on a model, bleed can easily set in as usually Grens are gonna outnumber Rangers. For everyone reading, I am not asking for buffs or nerfs just testing and trying to explain to myself what I am experiencing in game.
Your -29 for 40/-23 for 30 is great as I think it helps others(and I) quickly get a feel for matchups. I think this is probably the biggest reason why VG feel so lack luster. They not only get a really weak acc bonus at 30% they also get a fairly bad RA bonus of -23%. So even if they were to pick up a better weapon(MG42) instead of their STG they would still lose in terms of scaling to Cons/Penals/Rifleman/AIS as they are already designed to be matched up against LMGs.(Did not include regular IS as their VET is worse but getting bolster plus weapon racks makes the comparison really hard to make.)
This also shows why most mainlines seem to scale so bad compared to Cons. Despite having the worst starting RA they end up with a final RA of .71 and a great 40% acc bonus from vet. So against Volks, they perform better offensively and defensively as the game goes on while costing less upfront and overtime due to reinforce. Throw in a weapon upgrade such as SVTs for earlier power spike and it gets pretty ugly pretty quickly. All this seems to apply to Grens also but Grens at least get to keep good offensive performance while losing defensively.