I haven't tried the Advanced Jem fighters, but the regular ones that come with the ship are literally the worst combat pets available.
And steer clear of the Advanced To'duj. Standard To'duj do more damage. 90% of fighter damage comes from torpedoes, the regular To'duj has photon instead of quantum, and photon has higher DPS than quantum.
But elite scorpions are definitely the best combat pet available. The only thing that comes close is B'rolth birds of prey, and the Vo'quv is the only carrier that can use them.