Complex sentence: As stated above, several players joined up with former Wolf Gary Lee who had founded the Birkenhead Nighthawks who themselves merged with Wirral's other club, the Cheshire Cats and went on to have great success at the national level in subsequent years.
Split into simpler sentences: As stated above, several players joined up with former Wolf Gary Lee who had founded the Birkenhead Nighthawks. The Nighthawks merged with Wirral's other club, the Cheshire Cats and went on to have great success at national level in subsequent years.