A majority of the games that have debatable ownership have hardly appeared on more than one list, so the possibility of them even making the final combined list is doubtful.
I've also noticed some lists on the front page, not here in the forums, that either have the list maker clearly stating that there is no order, or they go alphabetically, or (most bizarrely) they include way more than 25 by having .5's and .25's and 0's. These lists are going to be ignored in the combined list. I know these people spent time and energy to make their lists, but if they don't follow the simple rule of 25 games in order from 1 to 25 then I can't use them.