Looking at it again now, I'm not sure I would cast the same close vote. It still doesn't strike me as being a particularly good question the way it's currently written, and - as mentioned in the comments here - may very well be a duplicate.
I think most of the issues come from that last spoiler tag:
What would happen if any or every of them would eventually die? Who could claim the throne? The one with the biggest army?
That's wandering very close to, if not directly into, the realm of wild speculation. The entire thing also reads (to me, at least) like a "I've read the books, I'm not sure who I think should have the throne, what do you guys think?" discussion-y question.
That's perhaps not the intent of the question, in which case it could benefit greatly from editing. I'd suggest removing the "Any other" part (that last spoiler tag) so it just focuses on those three who have explicitly been mentioned in the books, and making it clearer that it's an in-universe, "with respect to Westerosi laws" examination of the validity of their respective claims (assuming that it's not a duplicate).