IMO, it's not going to be much easier; that's the crux of issue at hand. The meer fact is you can't proof a negative. From your end you know she's been married only to you; from DOS/DHS end they have evidence under oath twice that the beneficiary admitted being married to 'original husband' in two separate interviews. And that marriage hadn't been terminated before marrying you.
I will say this differently, they will most likely revoke based on ineligibity of beneficiary because she wasn't free to marry you. This is where you believe you can easily overcome but I just don't see how that's possible (can't proof a negative).
But then again, you've established your plan to pivot the situation from 'ineligibity' to 'misrepresentation based on lies'; let's see if USCIS will bite on that argument. I doubt they will but I will never say never. I have read all the matters stated and all other relevant matters to those stated and I opine DHS has the upper hand. Perhaps, we will soon have a Matter of Elon vs DHS, if DHS doesn't pivot to the misrep route.