The Star Ocean series suffers from an absolutely awful case of Human Aliens - to the extent that many species of alien are still called "human," and the rest are almost uniformly Rubber-Forehead Aliens and Petting Zoo People - but the third game's Shocking Swerve could justify this: making all the races quite humanoid - or 4D-being-oid - makes them more identifiable for the Eternal Sphere's players, or possibly just saves work for the people who make character models. Bonus points because this might also work as a meta explanation.
I had one for the third game, regarding Fayt. Maybe it's just me, but Air Raid and Dimension Door, two of his most useful and powerful attacks, greatly resemble attacks the Executioners use. This is due to his Destruction Gene.