This is a great idea, but may not be practical for them to implement on the defensive side of things.
1- they would still need to develope a good base line defensive setup, because not everyone knows the game that well and new teams need to be at least on par with where they are right now.
2- with all the toons they need to be ready to store data from x number of users, for y number of characters.
3- not really an issue just an observation, we already have UI issues and this would need to have a complex setup to make it feel intuitive.
Allowing us to customize a setup before hitting auto would be nice. Being able to set priorities on special skills and some basic lock outs would go a long way to help.