Obscure heroes really are among my favourite genres in comics, and Captain Marvel certainly counts as obscure. I've made a study over the decades of obscure heroes - although there's no rigid definition and members on CB+ will know a lot of these odd characters, whereas the casual comics fan probably wont have heard of them. This Captain Marvel is good fun and has always looked to me like it should have been a Charlton invention from around the pre Ditko Blue Beetle time.
When I first saw and read this around '67, it piqued my interest as I was used to the DC heroes of the time and British heroes like Ace Hart etc. and that's part of the attraction. It was new, different, with a weird power and not mainstream. It's not that well drawn and the stories are daft. Actually, they're not well thought out. Doesn't matter to me, nor to some others it appears.
But don't you think that there have been other characters like this one, or at least ideas that sort of remind you of him? Triplicate Girl, later Duo Damsel, doesn't split bits of her body off but she splits of duplicates of herself. That X-Men character, Legion?, does similar. The Marvel villain who could blow himself up and re-assemble. And there's another one but buggered if I can remember who.
A cautious thumbs up from me.