I did exactly the same thing. I found the ACW needed a little bit of help because although it worked out the chords ok, some of them were slightly more complex than they needed to be. I knew my friend who sent the file would not have played some of the chords the ACW suggested so i simplified them which was easy as it was fairly obvious what the simple guitar chord should be. For example it suggested Dsus when all he did was lift a finger up!
My problem - and it may be yours - is that the original wave file was not recorded to a click track so timing wandered slightly. You may have got all the bar lines right with ACW but there is a video here about aligning to a click track in RealBand
https://www.youtube.com/watch?v=ZCRt2hQ137Mskip to around 37 minutes.
If you need to align the bars and you get the chords correct you can add as many RTs and loops as you like.