As far as different tones in furniture items go, I think there’d be enough variation in the tones of the wood to support it without being an issue. It would probably depend on the difference between the palettes more than anything - if the dark bits on the oak are as dark as mahogany, then it starts to look wrong, so as long as there’s enough difference between the dark parts of one material, and the light parts of the next, it should be fine.
I figured the “stone” would just be replaced entirely with specific types, but Genericite has a nice ring to it. I think it would need some more made up stone types to accompany it though, lest it be the odd one out.