Yeah I don't think it's trivial. If an algorithm made predictions on the level of html elements - whether an element should be a part of article body or not, it

Yeah I don't think it's trivial. If an algorithm made predictions on the level of html elements - whether an element should be a part of article body or not, it would be possible to combine probabilities or at least vote. But (a) it's probably a non-trivial modification (b) a lot of methods would also use some heuristics/postprocessing/have other quirks which make combining results difficult.