In the UK, the IR course is a minimum of 50 hours for a CPL holder, which can be split in various ways: sim/multi; sim/single/multi; single/multi or if you have a licence to print money then you could do the whole course on the multi! for holders of a PPL the course is 55 hours minimum.
UK CAA LASORS publication states a maximum of 25 hours in an FNPT I or max 40 hours in an FNPT II sim as part of the course. There is also a minimum requrement of 15 hours MEP flying as part of the course.
So if you already hold a CPL, the minimum would be 35 hours sim, 15hours aircraft. For PPL holders the 40/15 split you mention satisfies the min aircraft time requirement.