Well, they actually have had groups that you can create and select using control and the number keys since possibly the earliest game. I think you can also press shift or something to add selections to what you've already selected. Also, if you double click on a unit all units of that type on screen are selected so it isn't so bad.
I don't think that is enough to save my own interest in the title though. I think they really are scarred to take any risks with the basics of the game because they have been so successful with it. Maybe they could make some sort of offshoot of the game that sort of experiments with the nature of the game. They could leave the click fest rushed feeling to something more strategic and focussing on things other than war so that you can sort of pretend you are building a society. AOE is all about resource managment really.
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