>>23247757If this movie is in canon with Movies 10, 11 and 12, then Palkia, Dialga, Giratina and Arceus would all be relatively friendly with one another and not fight; you'd have a situation where those four would all know Ash and respect him. Realistically speaking all 4 of those pokemon are singular deities in the anime universe, there shouldn't be more than 1 of each and Ash saved all 4 at one point or another.
I could see how putting Groudon and Kyogre near each other would create a fight; and the 3 Tao dragons would probably fight. But there is literally no excuse for the Creation trio to fight unless its to break up the other fights or they're being controlled by some kind of foul magic.