This inertia of very large pages which resist any attempt to rework them is one of the more frustrating ReworkingProblems - you can see its effects in UseRealNamesRefactored here on meatball wiki. These swamps become permanently inhospitable, if you refuse to lower your standards below ReplaceWithDocument.
Therefore, blow all the existing content away, and replace it with a skeleton for a new, better organised page. If you have a full VersionHistory, drop a link to the prior version somewhere, otherwise save the old text at ...Archived and mark it DeletedPage. Then folks can come together and slowly move good stuff from the old version into the appropriate place in the skeleton, in a BarnRaising style, where appropriate. More importantly, they can add newer content, inspired by the wealth of prior discussion, that helps move the topic along a little.
An extreme CommunityOverContent version: automatically delete a page when it has been edited a hundred times. Now you get to build it all over again, and isn't that the fun part?