Complex sentence: In January 1920, in the post-Christmas downturn of Pesmen-Rubin's income, Disney and Iwerks were laid off; they decided to start their own business, a short-lived company called Iwerks-Disney Commercial Artists.
Split into simpler sentences: In January 1920, in the post-Christmas downturn of Pesmen-Rubin's income, Disney and Iwerks were laid off. They decided to start their own business, a short-lived company called Iwerks-Disney Commercial Artists.