You know how deer can have multiple points and elephant tusks are often different.
I think a lot of the ceratops in the picture are actually of the same species and just have a different amount of growth in their horns and neck ridge. The smaller ones are likely just younger...I can accept speciation (gazelle, white tail deer, mule deer, reindeer, etc) in the ceratops, but too many of these look too close together for me...
That’s my hypothesis. I suppose the only way to confirm it would be to do DNA testing of the various versions.
I did my 7th Grade oral report on the Ceratopsians, replete with my own drawings. I was in nerd heaven. The class remained awake.