Thats not the way it operates on type ratings from my experence.
You need each one to have a valid type of IR for each type of aircraft for some people they may have 2 one MPA and one SPA for the same type.
The SPA IR ME is valid for MEP class and SEP class ratings.
I think the SPA on a type allows you to fly SPA IR on a SEP.
Hopefully a CRE will be along to explain.