Well, in "The Breach" (ENT), Phlox said they were "
prodigious" breeders, not specifically
fast.
Also, much may hinge on Edward's emphasis of "
this particular species" in his comments here. Perhaps meaty-but-slow-to-multiply-and-easily-harmed
Tribleustes ventricosus is a dying breed on Iota Geminorum IV, being rapidly or gradually crowded out by
Polygeminus grex and any number of other varieties—cf. ants, frogs,
et al.—and falling victim to the very same abundance of predators that the latter evolved their quicker and/or more robust reproductive capabilities as a survival mechanism against in the first place?
Remember, Larkin both has a specific agenda...and is an idiot. (Who knows if the cause to which he shruggingly ascribes the effect observed—what else but the contribution of
his own DNA—is even the true one?) Further, recall what happened to Cyrano Jones when
he tried to have his small-but-fast-breeding tribbles genetically tinkered with in an effort to
stop them from reproducing in "More Tribbles, More Troubles" (TAS)...he (temporarily) wound up with
super-extra-meaty ones!
Weird alien shit be weird.