Complex sentence: Mike Gabriel also joined Men Without Hats around this time of constant membership turnover and by 1982 both Arrobas and Gabriel would leave to work with Pisapia in a new (pre-The Box) band, Checkpoint Charlie, before eventually forming their own group, Isinglass.
Split into simpler sentences: Mike Gabriel also joined Men Without Hats around this time of constant membership turnover. By 1982, both Arrobas and Gabriel would leave to work with Pisapia in a new (pre-The Box) band, Checkpoint Charlie, before eventually forming their own group, Isinglass.