I've actually moved to three AoE (Action Target Groups), instead of the one group called "Ground".

They are AoE_4, AoE_5, and Aoe_ShA.
The FTL DPS keys 4 and 5, each send next click to the relevant group.
As does Shift A.

In my current set up, ground target AoE's are on one of these three keybinds.
Have not found the need for more then three ground target effects across one team.