From what little I know about brakes I'd just say be wary of a set up that isn't designed for the car they go on!
Don't forget a brake I guess has a design that's brakes both front and rear in a ratio that should work whereas just having a similar size disc and calliper/piston set up just might not work as well.
Just as an example a change in pad material rent to back can create skimming and skipping so god knows what an unbalanced calliper/disc set up would feel like.
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