So far, in attack, Van Gaal has spent 116mil on Di Maria, Memphis and Martial. He has made 96mil on Macheda, Bebe, Kagawa, Lawrence, Welbeck, Zaha, Henriquez, Nani, Van Persie, Di Maria and Hernandez.
If anything, I would criticise the fact he hasn't signed enough attackers (or has let too many go) rather than suggest the he should be prevented from signing more. Whether he can get the best out of them or not is besides the point. If he gets sacked on February 2nd, I'd prefer us to have signed a promising attacker than not have.