Why not? The allegations cover at least 9 years of accounts and the accusations imply a degree of fraudulent accounting. Every line of those accounts will need to be scrutinised, every single transaction that's controversial will need to be forensically analysed and debated by the respective lawyers. And that's before the panel get down to discussing their conclusions and reaching a verdict, let alone the almost inevitable appeal if we're found guilty! If the PL seriously think that can be done in a couple of months they're even more amateurish than I already thought.
That's not whats going to happen. The scrutiny of every line in the accounts you describe has already happened over the last 4 years. You're describing an investigation, not a trial.
What will happen at the Judicial panel is the PL will present the things they've found to be breaches. ie Mancini's contract with Al-Jazira or whatever it is.
Then there will be an argument about whether that was allowed or not. When it's ruled on, it will clear about 30 charges and they'll move onto the next thing.
And there's not going to be an appeal. I think the lawyers in the press and social media have pretty much confirmed that; the only recourse for appeal is if there's procedural impropriety by the panel during the case.
CAS took 6 months. Even if we assume the PL is slow moving I can't see how it lasts 4 years.