Sorry to disappoint you but PvE isn't PvP. No amount of math can solve a variable mode which is why your question is illogical. Simply put; the best PvPers are those who are unpredictable. Swifty (I know, I know) said this a long time ago and what do you know, he was right. If you come into PvP with a set rotation, others can simply develop a formula to counter it - which is what wise PvPers will always do. This becomes very evident when it comes down to duels, although that itself, is unimportant.
What you can do, if you care for conversation, is to split the question into the formula as I posted above. Tell me what you're up against, what you have, what you don't have. What does your enemy have? Where are you? What warzone? What spec? What utilities? How geared are you? How geared is your enemy? What cooldowns does your enemy have? Did they get a lucky crit on their first hit vs you? What is their positioning? Are you near the objective? Are you close to team mates? Does your enemy have more than one nearby? Where is your PWalk?
You see where this is going?