I'd mentioned this in the past, but it's worth bringing up again since it's on-topic.
IMHO, as far as TOS only is concerned, my theory is that the "First Federation" never actually existed. It was a made-up organization just like the fake Balok puppet and the presumably fake outer shell of the Fesarius. The truth was that Clint Howard-Balok (or others of his kind) set up these elaborate ruses simply to test how aliens reacted to a seemingly more powerful force when in reality that was not the case.
The fact that we never hear from the "First Federation" again possibly backs up the theory.
IMHO, as far as TOS only is concerned, my theory is that the "First Federation" never actually existed. It was a made-up organization just like the fake Balok puppet and the presumably fake outer shell of the Fesarius. The truth was that Clint Howard-Balok (or others of his kind) set up these elaborate ruses simply to test how aliens reacted to a seemingly more powerful force when in reality that was not the case.
The fact that we never hear from the "First Federation" again possibly backs up the theory.