a good player can help keep things together and provide a bit of interest

...if they play on the beat.

Off-beat rock/pop-style drumming does nothing for traditional music and is of no earthly use in synchronizing a large group. It's just self-indulgent. An instrument that produces sharp, precise taps at exactly the right moment can do the job of a conductor and make a huge difference to a large group that's drifting out of sync; do it right and you can be inaudible to the audience if you want, it's the other players who need to hear you.