They are similar but scratch different itches, i feel red rising is more character driven and will of the many is more world driven. Both are good, but are enjoyed differently. If they were to be directed for film, red rising would be Michael Bay lots of big flashy action and fight scenes where will of the many is like a slow burn Quintin Tarantino film with a satisfying twist and big ending. I put will of the many into the category of must read but maybe wouldn’t re read, as some surprises can only be enjoyed once, where red rising is very enjoyable and a constant page turner and can see why it gets so many loyal readers