Depends on what you mean by "work".
IF you just want to use the setting and instead of the RMSS rules and creature stats... then yes it will work...
If you mean you want to use the MERP rules and add Professions and such from RMSS, Then, Not exactly easily.
RMSS uses a different Character and Skill development. Plus I believe there are a couple stats excluded from MERP that exist in RM2 and RMSS.
If you are talking about just using Attack tables and Skill resolution Tables, you will likely be just fine.