Here is a theory:
It has been shown that, while the ship's library is huge, it doesn't contain everything. Like it was said before, the 1701s are what 90+% of people are looking for, so that is what is in the computer. As for the NX and the older sailing ship, those would could have been parts of programs that where downloaded at a later date. The computer could have been program to just list the 1701s asked about the Enterprise and if there was a different Enterprise wanted, to assume that the user would have made a more narrow request. And in that case, it would uplink, find, and download the needed program.
Keep in mind, this ship has more than just a Starfleet crew. It has the crews families aboard as well. And I can see the Holodecks being used as an educational resource as well. So to have a child ask to see the Enterprise and list 11+ ships when all they wanted was the ship his/her daddy/mommy/grandpa served on, the child would get overwhelmed.
Thoughts?