This.
RegF, CAF only recruits 6 specialties: Rads, Psych, IM, GenSurg, Ortho and Gas. PRL can of course be anything, but if they deploy, they'd go in a "most closely matching" billet - the RCPSC ER doc would probably go as a GDMO, matching GDMO with CCFP(EM).
As for the statement downthread...