Look, we know how Arnold vs. Dorian would play out at tge Olympia...
Lets say on the day of the contest Doz is a few percent better than Arnold is. The night before the contest Arnold will book together a room for them to 'help' Dorian get ready for the contest. And that night Dorian will never forget. Arnold will just mix him up. Doz would come so ready to win but Arnold would just talk him into losing.
Doz is pretty smart but on the day of the contest it won't be that hard for Arnold to give him the wrong advices.
Plus if Doz shows up all fucked up on mushrooms and weed he'll be less hostile for Arnold.