They can set up and knock down the straw man that the exercise is some power grab and not simply training all they want but it doesn’t answer the question. What are they training for? They’ve been training for years and years and they have become very well trained for whatever is asked of them on on foreign soil without doing an exercise like this. Training to interface with American local agencies is only good training if you are training to crush a tea party rebellion. Learning how to interface with American civilian agencies does you no good in the middle East.
Military people get promoted and move up to higher positions - and some of them get out or retire.
You continually run exercises to train the people who are now in new positions.
One of the problems of this last 10 plus year war is a lot of the UW command and control has gotten real rusty.
While there will be a large number of ground troops there will be far more in Command & Staff positions working their butts off.