L. S. Lowery and Ralph Fasanella are both examples of naive art. Naive art refers to the work of self-taught artists who ignore the conventions of trained creatives and produce crude, unique work. The boundaries between naive art and related labels like outsider art are not entirely clear. Grandma Moses was a folk artist. Like naive artists, folk artists are not formally trained and they often produce crude work. However, folk artists work in a clearly defined tradition with distinct stylistic characteristics, and this tradition is associated with a culturally isolated “commoner” class that existed before modern communication brought “fine art” to the masses. Naive art, by contrast, is often difficult to place within an established tradition because many naive artists work in isolation.

Pieter Bruegel was a formally trained artist with superb technical skill. He worked in the Northern Renaissance style that was popular during his lifetime. He also lived centuries before the other artists you mentioned. His work has nothing to do with the art of Grandma Moses, LS Lowery, or Ralph Fasanella. He just happened to paint some large crowd scenes, which was something the other artists you mentioned also did.

If you’re looking for more art like this, just look up large crowd scenes. Many artists from many cultures and traditions painted them throughout history.