A speaker can easily be too big for a given room size. Larger taller speakers with more drivers are made for higher volume SPL capabilities to satisfy listeners in a bigger room. Often this requires a minimum distance from the speakers to the listening spot so the drivers output can blend and be coherent. That is distance requirement no. 1, speakers to listening spot.
Largrer speakers also tend to sound best when positioned away from room boundaries, walls and corners so that reinforced bass is not overpowering. Distance requirement no. 2, open space behind and to the sides of the speakers.
Distance requirement no. 3 is the minimum distance between the speakers for a coherent sound stage and its ratio to distance no. 1.
The final distance requirement is distance from the listening spot to the wall behind you. If your head is closer than 2 feet from the wall you will be in a bass accumulation zone and the speakers will have exaggerated bass.
Add up those three distance requirements for a given speaker and that will tell you if your room is sized for them or not.