Stars can be no more massive than WNh5 or O2 for any stars more massive than WNh5 or O2 stars can't exist in real life, and no smaller than Flare. i may resize you as i see fit.
i could say this could be that some random black hole captured those guys in the other system, but that's up to thesqueakyotter i don't think a black hole in a star cluster should be any bigger than this