You don't need power to be a great fighter, you do however need accuracy and timing. Obviously a combination of the two is ideal, but there isn't any use being able to fell a tree with a punch if you can't hit anything.
Precision-driven fighters like ivan calderon would always won on decision, he may be look impressive, dominate the compu box stat, but at the end of the day his general ledger will show his mediocre performance 33 w (6 ko)