It's called Natural Selection and it was pretty cool. I think people still play. https://www.naturalselection2.com/ The creators went on to make Subnautica.
There have been other takes on this concept too, but Natural Selection is probably the closest to your description. BattleZone (1998) was also a hybrid of RTS and FPS but the units were mostly computer controlled.
There have been other takes on this concept too, but Natural Selection is probably the closest to your description. BattleZone (1998) was also a hybrid of RTS and FPS but the units were mostly computer controlled.