Complex sentence: Halkirk joined the league for the 1993/94 season and were champions at the first time of asking but took 17 years before their next success in the 2010-11 and made it back-to-back success in 2011-12.
Split into simpler sentences: Halkirk joined the league for the 1993--94 season and were champions at the first time of asking but took 17 years before their next success in the 2010--11 season. They made it back-to-back success in 2011--12.