Sort-of-trilogies

Seems to me that sometimes sequences of three films are evident in cinema, despite no intentions of being related. Here’s my ever-growing list of ‘not quite’ trilogies. If you have any other ideas, do let me know.

The list moves in units of three, and the ‘trilogies’ are listed below;
1-3: The Che Guevara Trilogy
4-6: Disney’s ‘Animals’ Trilogy
7-9: Robotic Uprising Trilogy
10-12: ‘Once Upon a Time in (American Location)’ Action Trilogy
13-15: Terry Gilliam’s ‘Life of a Man’ Trilogy
16-18: Steven Spielberg’s...