CatTools only allows for the storage of one set of credentials for each of the VTY, AAA/local/TACACS and SSH authentication.
What you'll need to try do is figure out which set of credentials work with which device, and update the CatTools database accordingly.
I have a couple of questions though:
1) Have you entered all the devices into CatTools already and set their relevant device types?
2) How did you enter these devices into CatTools (manually via the UI 'Add device' function, or by using the Import from tab delimited file' option)?
3) Are your 3 possible sets of credentials all for the same type of device authentication (i.e. are they all SSH credentials for example), or are they a mix (i.e. some SSH, some Telnet, and some SSH with local device authentication also)?
I may have some suggestions as to how you may be able to update your devices, but the ways I've thought of so far would all require a bit of effort and some would require a knowledge of how to use MS Excel.