There is nothing wrong with that at all. Here is how I did it in order...

Private -- Private Multi add on -- Instrument -- Commercial multi -- MEI -- CFII -- Commercial Single add on -- CFI Single Engine

There are tons of ways to mix and match, but alot of it has to do with what you want to do (if its a career). If you want to go airlines multi time is a good thing to have, so commercial multi is a good thing to get first (that way you build a decent amount of multi time).