Complex sentence: Under new Lucchese leader Amuso, Casso became the family underboss replacing Mariano Macaluso who retired in 1989, although he wielded as much influence as Amuso.
Split into simpler sentences: Under new Lucchese leader Amuso, Casso became the family underboss replacing Mariano Macaluso who retired in 1989. Although he wielded as much influence as Amuso.