It'd be helpful if you sent an image, but:
1) Have you set up the prefix map?
2) Are the aliases containing the pitch/number that the prefix map will use?
3) Are the recordings in the same folder or separated?
The oto mixing the sound files is fine, if you have your pitches separated, and folders numbered they should be in order. Since most OS's use alphabetical order and file types to organize.
So if your folders are numbered the oto of that 1 folder shows up, the the next. If it's not it may or may not be in order.