IG will just keep feeding you small, cheap squads to tie you up thru your combat phase, then shoot you in their shooting phase before feeding you another cheap squad to keep you tied up thru the next turn.
You're forgetting that my guys have an 18" threat range. I'm going to be charging about 2-5 Imperial Guard units at once. 9-10 models (Minus casualties) can be strung out to about 30". That's a lot of targets I can go for. One of them is bound to hold during his turn. If not, then I should be able to engineer being within 3" of another
IG unit.
I can detach the warbosses for extra flexibility on assault targets, being able to assault at least 4 squads per turn. I don't see many
IG armies with more than 12 squads.
My only worry is rough riders. 6 rough riders can kill a Nob on average, before the rest of my unit hopefully butchers them.
But
IG are rarer than Hen's teeth around here, as are Dark Eldar, the one army I am really worried about facing.
Cheers,
Gazzor