First, we have a Director of Football. Squad balance should be on him as he's meant to direct football, over years.
Second, we had no pace whatsoever in wide attack and one striker and senior goalkeeper at the club, and £1.7m to do anything with to rectify it.
We need a left back too, and a playmaker, and another striker, and so on. It's not on Benitez that the squad he inherited was a train wreck and there was no money to do much about it.
We spent the only money on Gray and he's now probably worth £20m. It is what it is.