There are rules in the lower echelon of the Football League, which are designed to prevent clubs getting into the sort of mess the
Green Army have just emerged from, and the likes of Portsmouth are still in. The wage bill must not exceed 60% (I think that's the figure) of the clubs income. Therefore, even if there is a rich sugar daddy in charge, you can't exceed your allotted figure in wages.
This is where previously successful clubs (Championship level is successful for a club like the
Green Army) fall foul of the rules these days. The
Green Army were reasonably successful in the championship when the Japs

took over. Their philosophy was throw high wages at players, and the club will be successful. This attracted a lot of deadwood, earning high wages, playing crap football. Result - relegation to League 1.
We now found ourselves in League 1, with a team of crap players holding lucrative contracts. Funding from the Japs

immediately dried up for a League 1 side. We were able to pay off the better of the worse players, and let them go to other clubs. This still left a nucleus of crap players earning high wages. Because they were earning such high wages, hands were tied in regard to what could be paid for replacements. In fact, the
Green Army exceeded their limits to pay for what was still a crap team.
To cut a very long story shorter than it would have been, we've only just got rid of the last crap player on Premiership wages. However, the managers hands are still tied in regard to how much he can spend on players. The new owner is playing it by the book to make sure that we don't go down that same crazy rabbit hole on his shift.
Putting together a good team (even in the Fourth Division) is not easy when you have to work under such constraints. We can't go out and spend X million on new players. Not because we can't afford it nowadays, but because the rules will not permit it.
When you see what happened to the like of Rangers in Scotland, it's about time similar constraints were introduced and enforced in all divisions. I would guess that Arsene Wenger is one of the few premiership managers who could hack it in the real world i.e. having to work with a proper budget.