Or a ppsh blob? Or 2 commando squads one next to the other? Or 2-3 shock troops squads massed? Or... Or....?
I'm quite sure we're not talking about comp stomp games, so I don't know why you're here.
And its not like ISG is the only thing for OKW to counter infantry. Have you ever tries using AA HT? Or Luchs?
ISG is batshit OP, there is no denying it, there is no defending it, just a couple of incredibly biased jerks stuck in their own small worlds, defending it zealously like they were defending Hitlers bunker themselves. You're one of them.
And if you're such a fan of blobbing, shreck volk spam with 2 long range elite infantry of your choice works as good as ever unless opponent applies proper counters, which are harder to pull off, because volks just happen to counter most of them.