CANON is the only reliable thing we have to go by in these discussions.
A lot of FS1 ships appear only once in FS2 (Typhon, Lilith, etc).
When you consider it, the Lilith does seem a little too powerful, when considering its size. It seems much more like a corvette than a cruiser, it certainly is not deployed like other cruisers, but if used correctly it does not upset balance. What upsets balance is using it like any other cruiser, something no decent campaign would do.