While ATG make it more dynamic, all you really need is the target feature of a key map, e.g. slots 1-2 do action one, slots 3-4 do nothing, then slots 3-4 do something while slots 1-2 do nothing.

I create a Key Map set for each 'team' and then create mapped keys around a specific action, for instance in my WD/DH Key Map I'd have a Taunt key nad Piranhado defined. Each mapped key would have multiple steps (perhaps with 'do not advance to next for x seconds) managing the round robin of that particular skill; e.g. step 1 would target slot 1, step 2 would target slot 2, etc. I wouldn't bind a keypress to either key-map, I'd have a third key map that would be called something like "CrowdControl" and I'd bind that to a key, and on each key-press it'd do a key-map action-> Taunt and Pirahnado.

I don't generally mess with ATG for D3 because I rarely swap toons in and out of a composition, if I end up changing my composition, I create a separate key-map and consider that an entirely separate team. (e.g. I have a 3x Cru 1x Monk keymap, a 4x Cru Keymap, a 4x Monk Keymap, a 4x Wizard Keymap, etc.) If I wanted to go back to one of the other teams, I still have the key-maps to do so, and while I might have to move skills around, having the key-maps name the skills they are intended to call helps. (as opposed to a SPAM key map that just sends number keys...3 weeks later trying to figure out what 1-> 1/2->2 was supposed to accomplish.