SV first stage had 5 engines, vs 33 on the Starship's booster. Which I think answers your question :)

I don't know about other metrics for comparing engine efficiency. But the design requirements seem quite different here - they have to be restartable (not something the F1 engines on the SV had to worry about), probably more steerable, and able to throttle down to quite low power for landing. And presumably the fact that there's so many in an array also imposes its own constraints on the design.