As the OP mentioned, I think a key issue is that the range decision right now is not a decision at all. You always want your ships to engage at their optimal range, regardless of the secondary bonus of the card. So I think that is the wrong decision. I think the decision should be similar to Lo_fabre's idea, but even simpler: 

1) Hold Back: All ships stay together at the longest optimal range for some of the ships.

2) Optimal Range: All ships move to their optimal ranges and stay there as best they can.

3) Charge In: All ships stay together and move towards short range.

Now since Optimal Range is likely the best tactic in general, you could then give the other tactics some secondary benefit....or simply make that one more tactical choice the player selects.

At least, I would like to have the possibility to split my fleet into groups and assign different combat stance to each of them. I know they don't want us to micromanage the battles but I don't think it's that difficult to implement. It would be more satisfying to give combat orders this way in my opinion. 

The combat of ES1 is more satisfying and complex than the one we are getting in ES2. A major step backwards :(

And herein lies the beginning of the problem with the current iteration of the combat system and where it relates to Ship Micro.

There's no dynamism. Even at the higher tiers, you're given a battle plan, you'll be able to drop your ships into flotillas and... that's it?

That's the -least engaging- approach to combat I could imaginably conceive, it's one step above pure auto-simulation and the only incentive it provides is to either stack for specific battle plans or punish lapses in concentration if you brain fart and engage the wrong battle plan. It actually makes ES1's auto simulation a better idea because at least THERE you could just have it deal with "default" and not worry about the idea of accidentally setting your fleet to engage at long when they're all rigged with short range weapons (not sure if you can -entirely- skip the planning phase and just tell it to self optimise but that would be the logical conclusion).

For what you're suggesting or what I'm suggesting there would need to be a significant retooling of the combat system, your idea would require state triggers to be present and for the player to have access to them, that would vastly increase the battle space vocabulary but would entail giving players something akin to a simplified "scripting language" made up of lego style blocks or cards that could be played as part of the battle plan. My idea would require retooling of the battle plan phase itself with a much deeper level of planning required and the ability to save custom plans and then apply them to specific fleet comps. Both of these are significant undertakings, but both of them would allow the player a much greater level of agency in the battle space.

Either option would be a good start, but I'd not want to be the fly on the wall for the meeting that says "We're going to have to go into the combat system and revamp it"

I agree with basically everything in the OP. Dominions pre-battle order system is a great example of how you can have battles with strategic depth and still eat your auto-resolve cake too, and most of its systems would translate pretty well into this game.

You just made me realize how amazing Dominions battle scenes would be with some quality art direction like we have in ES2 would be though and now I'm dreaming of a game that will never exist.

Good stuff here.

I think they can make a card system like ES with pre-made strategies, like:

• Pincer: Split in two to try to flank enemies.
• Surround: Your big ships stay in front and long range, while your small ship tries to get close and take enemy's rear.
• Sniper: Your long range ships lead the battle, while short range stays in front and try to stop any charge.
• Charge!: just run to short range everyone.

Of course there may be lots of more tactics unlocked by techs (maybe each hull unlocks specific maneuver, while each military tech unlocks another, and of course heroes has special moves).

I think it partially fixes the loss of tactics, and at same time maintains the simplicity.

Indeed I thought it will be this way when I see the "Xenorian pincer" in one of first images released.

That's only half of the issue, you'd also need to have separate maneuvering orders for "Long" "Medium" and "Short" range optimally, which means for three flotillas you'd want a 3x3 grid of possible orders. At that point then you'd have potentially, a working and interesting system, if you can then -save- those battle plans into a "playbook" which you can then at a glance choose which page from your playbook you'd like to adopt, that suddenly elevates the combat from being a non choice to a set of interesting and discrete choices. Particularly if within that you can set which ships within a flotilla take the lead, and what their designated targeting order happens to be.

Taking -your- suggestion and going at least three steps further, then we get to an interesting and useful system. But it needs to be overhauled, not just tweaked. There needs to be a conceptual rethink in terms of "How do we give the player agency and allow them to create interesting options, how do we allow the player to set up fleets that express unique and diverse options and how to we go about allowing them to achieve that", pre-set battle plans which force players down prescripted routes restrict that, but by separating the phases back out and giving players a wide set of tools at each phase, you can at least improve the vocabulary the player has in terms of what they can -do- with the battle space.