well you aren't really factoring in skill right now
As far as I know, the easiest way to get as much stacks as possible when you have an opening is E auto auto (2nd auto isn't really realistic as it takes too much time without AS built) WQ (animation cancel Q) auto and if possible, titanic hydra active auto
but this is not a teamfight combo
Also, E is still a CC and can be easily used to interrupt the enemy mid-trade as it is a pull with technically 2 CC's (pull and tiny ass knockback when their character hits darius and bounces back) and a viable duration. Used at it's prime can basically be on the equivalent of a Blitz Pull with only less distance, not to mention the hitbox is "3D" so you can pull enemies farther than what the animations show, or enemies may not be pulled even if the animation shows they should.
As for anything outside of 2v1's or 1v1's (teamfights)
- last hitting a target with R is the same thing as last hitting a minion with an auto attack, except you need faster reflexes and prediction and a bit more luck. Only pressing R is very rash and is suggested you auto W R instead ( with AA cancel ). And an enemy being caught out lets you snowball even easier. However I'll admit that you need to take out the backline first as they deal the most damage and the frontline ain't gonna let you waltz in there. So a flash is almost mandatory if you want to snowball the teamfight to the point where it completely turns it around. I'lll finish that part later though
