Complex sentence: However sculling ability and sweep-oar rowing ability are not the same, and a powerful and accomplished sweep-oar rowers may not be able to demonstrate their ability in a single scull where balance and technique are more critical.
Split into simpler sentences: However sculling ability and sweep-oar rowing ability are not the same. Powerful and accomplished sweep-oar rowers may not be able to demonstrate their ability in a single scull where balance and technique are more critical.