You neglected Unchained, along with the potential added Critical chance, which negates up to 10% of the Damage reduction from Defiance. (In the long run)

Only reason I'm even bringing this up is because I want to test this myself. I also think that this added power from Cross Skills is only based on using Damage Boosting cool downs a ton, but the titan fight intrinsically removes their effectiveness by forcing a lot of movement, and I don't think they will be as effective as you can show on a training Dummy. Where as Defiance with Berserk/Inner Release/Unchained are short enough bursts, to get their effects used up 100% of the time. + Using Inner Beast also Ignores the Defiance penalty as well. So during Unchained toss up an Infuriate, and go to town, then back to IB Spam.

OP Please follow Gamemako's advice here, I'll do some more testing when I have time to log back in, since my advice is not based on using Marauder.

Also, what is the added Strength from the Warrior Crystal?