Just a minor note regarding the issues Insaniac brings up:

Yes, that's certainly an issue. It's roughly accounted for in the spreadsheet by allowing you to specify an average amount of time beyond the recast timer for you to be able to use the abilities. The default is 5 seconds, which corresponds to being able to use the ability anywhere from 0 to 10 seconds after the recast is up, which should cover most minor fluctuations. It does not, however, account for lost melee damage from the times you may need to turn away briefly.

As for the conal issue, no, you don't want all the DDs stacked on one side of the mob. At the same time, most of the DDs don't want to be in front of the mob anyway, so usually they'll try to let the 'tank' keep hate as much as possible rather than spin the mob and have to eat that doom move, which in turn makes it easier to land SA.