My friend wants som rcs so I brought him 5. Checked aquadvisor and the only fish he has that they warned about keeping with rcs was the kissing gouramis.
Kissing gouramis will definitely eat any adult and juvenile shrimp in their tank, so no, they're not compatible. Keep in mind that in general, any fish or shrimp small enough to fit in another fish's mouth will end up exactly there. What other fish are in your friend's tank?