I agree.
However, while it seems to me that sixth-stage commands like "cast summoning/damage/buff" or "cast damage/buff/summon" should be easy to implement or add (since each would merely require an additional set of number costant definitions for the tactical AI spell selection, i.e. a different weight for each spell), I doubt that we will see such improvements:
1. While it would be nice to have this control, it certainly means longer turn times for human players: In Dom2 this tactical control is already important, but it could be neglected in many cases with a player using some template scripts saved to the scripting-shortcut-keys. This speeds things up. A powerful tactical setup means that one really has to set up the army again and again for each battle individually. This is clearly a good and a bad thing...
(I would like it, but I would never finish a turn anymore since I suffer from being pedantic... 
)
2. Such control will most certainly exploit much more inbalances within the game. A game with thousands of monsters and hundreds of spells just
cannot be completely
balanced without being boring. More tactical control will allow players to exploit this, making balancing even more difficult. The tactical AI evens things out, because everyone has to live with it. It helps the game to appear well balanced.
3. More tactical control will make playing against computer controlled nations probably more easier. In my humble opinion Dominions is and
should be a multiplayer-only game. However, the single-player community seems strong from what we can learn on this forum, so while everyone might welcome more choice for the tactical AI, players will then complain again about the "bad AI", for whatever that really means. For me it's good enough to learn the game or to test a map...
So, summing up, for these three reasons, I do not expect any major improvements for Dom3 in this aspect of the game. Maybe some commands to make light cavalry units useful somehow, since this has been extensively criticised for Dom2 in past time in my perception. But who am I to guess? Let us wait and see...