We are basing cast caps on timelines and continuity. So in the case of the Fate/ series, Fate/Zero and Fate/Stay Night would be counted as one. Fate/Grand Order on the other hand, being another continuity and timeline, would be separate.

So things like Persona and the Tales of series are counted separately by game with the exception of sequels like Symphonia's.

If you have any further questions, let us know! If we're not familiar with the series we can take a look at it.