Dragon Ball movies always had good animation but lacked in story, except for DBS Broly.
It’s pretty clear when you see them because the villains are always poor developed and are defeated by a power up came from nowhere; I think that it could be interesting to see some character rebooted as Broly ’cause the villains aren’t bad per se, the problem of the old DBZ movies is that they were done for festivals and were light vision, nothing so developed.
But thinking about Lord Slug that is a namekian as Piccolo make me curious about his past, you know, why is he a super namekian, what does it took to him to achieve such power? What had he lost? The problems of those movies is that they do not answer many questions and when they do, they do it bad.