I would rather have ai automated combat with stacks of doom. Assign AI generals to your armies so they can fight (you still move them). Then watch the simulated battle. Fighting is over in a single turn. Want to win more wars? Get better troops, better logistics, pick better battles, pick better wars, and pick better AI generals. You have to work for all of this.
With slight adjustments:
1. No Stacks of Dum, but Stacks of Possible - what you can Possibly concentrate in one tile changes with the Terrain, Biome, Technology, etc and continues to change as the game progresses. This is such a no-brainer it has been adopted by two recent additions to the '4x' genre:
Humankind and
Millennia, and I believe the Still Developing
ARA has a version of it.
2. Provide some agency to the gamer in the Battle. That can be as little as deploy the army on a battlefield and give a very general order: Defend, Attack, Flank Them, etc or, for those that like tactical interludes in a Grand Strategy game, move the units or combinations of units. That latter should NOT be the default, but a chosen option for them what likes it.
3. DON'T provide complete control of a Battle. First, because it never existed, but second and more important, because it inevitably leads people to want to exercise that control to Maximize their chances of victory. That simply puts 1UPT down on the battlefield and makes gthe battlefield a distraction from the 'real' Grand Strategy Game you are supposed to be playing. This is a fine balancing act, but there are Clues how to Achieve it:
Great Generals - could be attached to a Unit or combination of Units to provide complete control of those elements Only - see the common action of such IRL generals as Alexander the Great or virtually any European Medieval commander or even such recent Generals as Rommel or Guderian in WWII, who both showed up wherever the fighting was tense and important.
Uniques - Both Unique Units and even Unique Tactics applicable to the battlefield: everything from the frequent Roman tactic of having an un-named Tribune grab a bunch of Centuries, Maniples or Cohorts and take them where they were never originally intended to go and win the battle, to the ability of more modern forces like the
Grand Armee French or German troops using
Auftragstaktik to do much the same thing regularly.
Professionals - troops that have been doing this battle thing for a while full-time learn things that are nearly impossible to teach to amateurs: so units with Promotions could allow you to give them more precise orders or order them to do things other (amateur) troops simply cannot do.
Bottom line, an army of units that are Professional and/or Unique and led by a Great General should be a very fearsome thing: they should, on a regular basis, mop the floor with even larger armies of Amateurs led by a Less Than Great General, and do it without the gamer having to give them every order and move every single unit.