I can go either or. Having numbers does give us (or maybe just me) a clear idea of the combat situation (narrative battles can get ambiguous), but on the other hand, it has the potential of becoming very distracting. Possibly to the point that players could loose interest. You should also expect some confusion in the first few battles. 

If you do implement numbers, how would you do it with this version of The Spirits Within? Maybe you can write an example of a typical combat (tutorial), instead of simply writing a list of rules, so that we get the feel of it?