I’m personally REALLY hoping they don’t adopt a Humankind esque combat system
I started out really liking it, smply because it did condense battles into the equivalent of One Tile, One Turn, which I think is a basic necessity to make a Grand Strategic game like Civ make any sense at all. After a couple of months, though, the negatives of it became apparent:
Using the game map as a tactical map resulted in 'battlefields' with far too much complexity and terrain on them for any battle fought before modern firearms
Each battle took time to game out, and in the late game a war between two major powers might produce several battles in a single turn, turn after turn. Turn Times went from a minute or less to half an hour or more each and everything else in the game except the battles slowed to a crawl.
There are still a lot of things I like about HKs way of handling Unit attributes, but I am much less enthusiastic about any 'drop down' tactical system after experiencing it in HK - and in Millenia, which goes the other way from HK and does not allow you to play out anything on the tactical map: you send the army in, the game plays the battle and tells you what happened. The battle graphics are primitive beyond belief, and the gamer has no input or agency in the battles at all. That seeds up the game enormously, because not only do battles take no player time at all, but the player quickly gets tired of the whole thing and drops the game. Saved me a lot of time anyway.
I didn't like the HK combat system, but I really like the similar AoW4 combat system.
Breaking combat off into a tactical map is probably going to be the natural evolution for the 4X genre. It allows you to have stacks on the world map and 1UPT in combat, the best of both worlds. It allows appropriate unit scale, so that archery units aren't firing arrows across the breadth of Italy, for example. And there should be an auto-resolve option if you can't be bothered to finish off that lone barb Scout by hand.
The problem with HK combat is that they made it needlessly complex, particularly sieges. I played HK for the VIP program and for months after release and never got the hang of sieges.
You could certainly discern a 'trend' in separate tactical maps/drop-down combat systems in new games like Humankind, Millenia, and the near-release ARA, all of which are using that kind of system.
But, as noted, Humankind and Millenia have both produced battle systems that are immensely unsatisfying. I have not had a chance to play or view any battles in ARA, so will probably have to wait until it is released this September to comment, but the 'Trend' does not impress so far.
I may be the only gamer in the Hemisphere that cares, but one problem I have with virtually all the combat systems mentioned and in Civ VI is the Level of Command. That is, supposedly you are playing the Immortal Omniscient God King/Spirit of the Civilization or Culture, yet on the other hand in battle you are the Shire Reeve telling each of your archers where to shoot, the Captain commanding the unit of musketmen, the Knight Banneret leading a charge of knights. That's a lot of hats to keep switching out conceptually, and it frankly blows the immersion and identification all to pieces for me.
Again, maybe it's just me, but I would like to have the level/degree of control and direction that an Absolute Monarch had, but No More. That is, I can tell the army how to form up on the battlefield, roughly , and whether I want them to attack, defend, maneuver, take a lot of prisoners for the Altar on the Temple of Kukulcan, or give no quarter. But exactly how each unit carries out the general orders is well below my Pay Grade, so to speak.
If you want complete control of all details in a battle scenario, play Chess or Checkers, or one of the myriad of battle combat video games. I just don't think (and again, only my Opinion) that such detail is appropriate in a game whose smallest turn is One Year and whose focus is building a Civilization over centuries.
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