My understanding is we're suing for damages, loss of earnings, impact of relegation etc whilst you held an unfair competitive advantage.
From that perspective, I can understand the club's arguements however, I personally think it's a waste of time and something we could do without.
On the face of it, I agree with you, I don't think the case is really that valid but I'd assume our lawyers have advised the club have a valid case hense the initial intention to sue if you were found guilty.
For me, what's done is done, no point looking at the if's but's and maybe's.
You've admitted to breaking the rules, you've been proven to be guilty of that and you've been given a punishment, harsh or not, and that should be the end of the matter.
My only take really in this as I said before is that I find it ironic Everton have been dealt this penalty at a time where the odds are heavily in their favour to survive.
That's not their fault, it's the Premier League's for taking as long as they have, but effectively it's probably worked out kindly for them anyway.