I think it is a great idea to save money, although if you are going to do a multi IR and haven't done it yet, it would probably be helpful to do the MEP and the IR on the same aircraft type, just to save any time finding your way around a new aeroplane....
I did the multi and IR first and it was fine doing the CPL afterwards - I was probably more relaxed going into the CPL actually as I had the IR out of the way which was the one I was most worried about.