"So it may not be in their best interest to go to trial?"
I would think not. Worst case scenario for her going to trial is the Judge gets ticked off at the deception and orders no support. Middle of the road it's reduced. Or Judge is ticked but goes with mediator's recommendation anyway and admonishes her not to waste the court's time. There is NO way to predict what the Judge will do.
Didn't get her latte that morning, someone dinged the car, she's irate already and it goes more favorably for you. Or wife got a bonus check and they will be able to take that vacation to Aruba without the kids, turns out the roof just needs a couple of shingles and doesn't need to be replaced, got the closest parking space today for the fifth day in a row, and he doesn't care about the deception and glosses over it and awards her 10 years support because he is feeling generous. Now you are taken for three extra years more than what the mediator recommended.
No one here has a crystal ball to forecast it. Your attorney is the one who knows the judge who will hear the case and their temprament and style of rulings the best.