I am going to assume this is a question desiring a real answer, not an argument.
So, here goes...
We have seen enough of a teaser of emails from COG legal staff to know that there is some what of a case there that Frisoni and Tindall were 'significantly involved' in the contract with IA. It seems very reasonable to me that what COG legal staff introduced to the court was really just tip-of-the-iceberg. Thus, I conclude that COG has a very, very strong case which is very likely to win, should this go to court.
Therefore, they don't have to settle. If the case goes to court and they win, it just means they are back at the table, negotiating with IA.
Now, from IA's side.... It seems to me again that they have a week case should this be decided in court. Were they to lose in court, they have no place to play.
So, what risk does COG have right now? The very small possibility in my mind that IA wins in court. That's all. Current City Council seems to have figured out that IA as Arena Manager is a loser for Glendale. They seem to have decided that they would like the team to be there, but if it can't happen, they are OK with that. So, in their minds, the risk of the team leaving is no risk. Thus, COG has very little risk in the negotiations.
What risk does IA have? Well, effectively, right now, they have no place to play. Their window to negotiate a sale out of town is closed. The Suns' arena is not an option. They literally have no place to play. If they run the case to a judgment in court, and COG wins, the lease could be cancelled in mid-season. Then what? This is a lot of risk.
Thus, my conclusion that COG has all the leverage.