I suppose the coach is supposed to be doing this in the game engine.
So, one nice step in this direction might be to just publicize the changes the coach is making. Ie, that way you could see that even though you started the game in Low Post, now that you're down 15 the coach has given up on this and shifted to a style with a faster pace. Just seeing the coach's changes to your game plan would be a step forward. And a needed step towards allowing the player-manager to do more.
A system where a manager can set up conditions for changes would be most flexible. Then the manager could program in certain changes for certain conditions. Ie, change the offense if ahead or behind. Could be very flexible. Also probably a bear to test to make sure certain conditions don't 'game' the game engine.
Maybe as a first simpler step, just allow three sets of tactics choices ... ie, you can set your offense, defense, depth chart usage and response to fouls for just these three conditions ...
--Normal--
--Down by 12 or more--
--Up by 12 or more--
To me, I don't so much want to automatically change by quarters as I'd want to change per conditions in the game. In the above, it wouldn't be nice to be trying to defend a lead in the 4th Qtr, with a team fighting off foul trouble to key players, and to find oneself in a fast-paced, full-court pressing sort of game just because that's what the plan said to do in the fourth qtr. I'd rather have that triggered by my team going behind in the game.
just my $0.02 worth. :)