There has been a lot od discussion regarding hands off combat in ES.  

Combat in ES2 is all about being an emperor.  Amplitudes vision is quite clear on this point.  This game is not and was never intended to be hands on when dealing with combat.  You are the empire builder not a fleet commander.  If you want to play hands on combat then lobby Total War to make a space game.  They are masters at RTS combat.  I like both aspects when they are done well.  ES2 in my opinion sets out and succeeds in the direction that this game is taking.  Make your choices and the rest is up to the gods of space.  It's galactic war where your heroes are the fighters.  Most 4X game fail miserably in direct RTS combat.  The expectations are always never met.  Crap graphics and mundane control mechanics have sent many a 4X game into oblivion.  Homeworld remastered and Total War Warhammer are the finest example of RTS done right.  ES2 vision of epic space battles between great empires is a refreshing take on this.  I can see a time when we might get to see real cinematic battles like many of us have seen in the best SI FI shows.  Bringing RTS to this game will ruin its pacing.  

What can be done to improve ES2 combat.  

Tactical over screen during battles.  This will show a god view of the battlefield, top down view showing all ships in the arena.  Tactical view also shows high threat targets and projected coarse.

Ability to designate hero ships to enter the combat part way through.  Imaging one of your flagship jumping into the fray mid way through and crushing your enemy when all looks lost.  This would provide innovative play and a reason to play out the most important battles.  

battle tactics at the start of conflict needs to be greatly enhanced.  Nelson at Trafalgar split the French fleet in two and went at them from both sides.  A battle plan needs this type of forward planning.  Options before combat is the key to diversity and ultimately victory.  I estimate at least eight strategy battle options available will provide unpredictable outcomes where the player has to play out the battle to see if there plan works.  It would also allow a smaller specialised fleet to overcome a mush larger one.  

Technology options for combat.  Without radar Britain would now be under German occupation.  A technology can drastically alter projected combat outcomes.  You could infiltrate an enemy fleet and hamper there effectiveness or send a virus during combat.  All these decisions and options need to be available during the battle plan phase.  You might only have two EMP devises available, when do you use them.  Which battles can you let slide.  Tactical options are the best way to effect the outcome in hands off combat.  

The American colonists kicked the British out largely because they had a clear moral stance that allowed them to mount an effective resistance.  Political cohesiveness can provide extra diplomatic choices that some battle plans could use.  If you have a strong senate with a clear mandate then a battle card buff could be available.  Cold war tactics could be employed in this area.  Imagine another empire has attempted to assassinate one of your heroes or even you the emperor.  A measured diplomatic reaction would be to take out a shipyard or takeover a single planet without declaring all out war.  The reasons we go to war are varied and often are a reactionary process.  I would like to see some innovation in this area.  This would be a great concept for espionage.  Infiltration is another tactic for creating a resistance.  Victory through destabilisation.  Sending populations into another empire could influence a star system to change policy or inflict penalties through negative buffs.

Just some thoughts on additions to combat.  

I agree. There are other games in the 4X space genre that have unit by unit combat, but I think spec-tactical overview battles of Endless Space 2 reinforce its slower, turn-based pace. 

Ideally, provided we have a rich tactical level of planning our battles (and I think there are good signs of that in GDDs , i.e. taking into account anomalies around the planets where the battle is taking place), I would definitely want to watch and replay some of the battles. 

Also, it would be good to have the instant feedback of your choices as in ES1 where if you successfully countered your opponents strategy, your own got a boost.

Interestingly enough, the concept images in the GDD showed exactly what you describe: splitting your fleet into distinct units and having them perform strategic manoeuvres  like, err..Xenorian Pincer. It would be great to be have heroes with skills that add/unlock new manoeuvres. Unfortunately, at the moment it's pretty linear (long range, medium range, close range). I hope it's just the limitations of Early Access and not final design.