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Not sure, I just run the front one with the standard rear. They do rear mudflaps generally, I have them on other bikes, but I don't know for sure how they would sit given the slightly more horizontal angle of the rear mudguard where it finishes. On larger-wheeled bikes they drop nice and vertical from the end of the guard.
They're only cheap though so if you're ordering the front you could give a rear one a go.
This is the best front mudflap I have tried: https://rawmudflap.uk/product/folding-bike-mudflap/
When mounted it makes a deep box shape which really limits spray and shit getting all over the bottom bracket area. Really good bit of design.