Apart from anything else Saints don't have the resources to do a Man City, money is almost meaningless to them. They are quite capable of driving the PL or FA into a financial disaster.
I think also what we did was quite stupid, regardless of the appropriateness of the rules, we'd signed up to them. Most Saints fans recognise this with complaints mainly centred on emotive media reporting and (possibly, lets see) excessive punishment.
The mind blowing entitled attitude of Man City supporters have put all this into context. A great shame as I used to see them as the more reasonable bit of Manchester. They actively want the PL to fall over this rather than be punished, they completely miss the point that they signed up to these rules even if not agreeing with them.
I remain confident the impact of our punishment will harm Saints more than any levied at Man City. Politics will also play a part in this.