If Floyd had no prep time, like he was told today that he's fighting Ronda MMA rules in 20 minutes, I'd still put my money on Ronda.
It's really easy to get a fight to the ground when you're fighting someone who's literally NEVER had to defend a takedown in his life.
I'm not sure why people would think it would look much different from Art Jimmerson vs Royce. Jimmerson was bigger/stronger/faster than Royce, and the gap in striking skill was similar. Jimmerson wasn't as good as Mayweather at boxing, but honestly Royce was not as good as Ronda at boxing either, because he never trained it at all. At least Ronda works the mitts.
Don't forget, Ronda got Holm on the ground, and Holm was fully prepared and trained to prevent that from happening and it still happened. So now take Floyd who isn't trained to prevent that at all, and things may not go so well for him.
On the flipside, if you gave Floyd just a little prep time. Like let's say two weeks of training to defend throws, then yeah I think he schools Ronda.