Complex sentence: Alex Lowe and Jo Wyatt joined the cast in 2014, Harriet Kershaw joined the in 2015-2016,Maria Darling joined the cast in 2016.
Split into simpler sentences: Alex Lowe and Jo Wyatt joined the cast in 2014, Harriet Kershaw joined the in 2015-2016. And Maria Darling joined the cast in 2016.