There isn't much in the canon on this subject - the Nephilim warships are only described in the official guide and in Syd Mead's art book:
From Origin's Official Guide to Wing Commander Prophecy:
Orca - "been known to occasionally employ interceptors"
Hydra - no reference
Leviathan - "as many as several hundred fighters"
Kraken - "a small number of interceptors"
Tiamat - "a ful complement of fighters -- as many as a standard carrier could contain"
Syd Mead, describing a command ship: "The 'capital ship,' above is immense in story scale, measuring avout fifty kilometers in length. The command level is at the top. The spherical front end opens in an iris-like maw that can spew out hundreds of bio-mechanical fighter ships to form a frightening attack." (image:
https://cdn.wcnews.com/newshots/full/mead1-1.jpg)
The internal shipsalien design document says:
Orca - "Some destroyers may also embark a handful of interceptors for self-defense."
Hydra - "it carries a small hangar region for the support of several fighters"
Leviathan - "The number of fighters embarked may be as high as several hundred"
Kraken - "It carries only a few Interceptors for indigenous fighter support"
Tiamat - "It has the fighter complement of a carrier"