That's the easy part
Average points deduction for guilty charge is 4 points, and this is with helping the enquiry. A 456 point deduction wouldn't be sufficient. It would only lead to the Championship. That's why I see it as a big enough points deduction for relegation plus a transfer ban for 3 to 5 years. The transfer ban would hit them hard. Most players would go out of contract in this time and would be free to leave.
And if the counted wage bill is really over £400m they would be in real financial trouble. That would be more than their income even if not a single sponsor left. Their share of the TV rights was about £277m.
Then you have what must be about £200m each year in amortised transfer fees. They could sell players, but the amount carried over would be minus the amortised amount still left. Even then they could only spend a total of 85% of the total figure.
Their best way out would be to sell from their academy. All expenses are not counted but transfer fees would go straight into the income pot. But considering with keeping all the sponsors they would need to cover about £200m. Then with the 85% limit there's another £60m on top of this. They could only count 85% of the money received from their transfer fees, so would have to raise £300m from their sales. So just selling academy players wouldn't be easy to make the money.
On the other side they can overspend by £15m in the Championship and their TV rights should about double this. But that only raises about 10% of what they need.
And even better is everyone would know that they're desperate for money and desperate to sell so won't be able to hold out for big fees.
So yes we would find out very quickly what they count as wages in the Championship. It would either be armageddon or just having to sell a couple of players. I know the rules of UEFA were shown as evidence, but the Championship rules are totally different.