Please take a look at LOTRO for the proper way to design end game dungeons

[givemeraptors]

There is a ceiling on most end game fights that requires a certain ilvl to pass, you can have the best rotation in the world, it won't matter if your DPS isn't up to speed.

It's called a minimum ilvl and it's required for all post-50 content.
So actually yes, if you have the best rotation in the world (plus can dodge etc.) and meet the requirements to enter the fight you will win.