[Hunpecked]

Dogscoff is right about the need to synchronize FTL introduction in fictional universes such as SE IV. In fact, if you also make this FTL tech the basis for STL propulsion, weapons, "shields", communications, etc., then all intelligent races start at essentially the same tech level, whether they've been in space for a year or for a million years.

Of course, as others have pointed out, even at STL speeds some species should have already overrun our galaxy.