I see and read all the formation comments, however I just want to address the fleet comments. Sins2 fleets are much more sophisticated than Sins1 and are simultaneously easier to use (and they aren't done yet).
Jump together - all grouped, not grouped, some grouped
Super easy to create multiple fleets and send each as a group or not. Have the secondary fleets follow the primary fleet if you want to maintain more coherency. This was very clumsy and confusing in Sins1. It’s also faster and more fluid to hold a hotkey to send them in one of 2 modes, rather than having to toggle the button. Also, there is a setting to pick your preferred default movement mode.
Form fleets - group ships together in an easy one click unit
Its not one click as you have to open the menu and click the button. Sins2 is easier, and more importantly, more fluid. Band box your units (or select/group whatever way you prefer) and right click the left side (or a main view fleet icon) to either make a new fleet (or add to a new fleet). Probably add a hotkey to make this even faster for advanced users.
Engagement range - helped ships stay repairing etc
Likely coming in a future update. Code already exists as that is what the Derelict guardians already use.
Retreat - a quick button that got all ships to drop what they were doing and retreat to the nearest gravity well. Great if you are occupied or the game was chugging and things were hard to click.
All fleets are on the left. Click it and right click to any location - even easier if you have planets on the left as those icons are stable and easy to click even if the game is chugging. Same number of operations without the interface bloat.
Auto Attack - off/on for all ships with one button
In Sins1 this meant don't move and don't attack. We figured the 'don't move' is useful to keep but when would you not want the ship’s weapons to fire? Hold position became its replacement and made more explicit than doubling up the duty of the attack button.
Move with formation - abstracted by needing a second key to disable it
See above under Jump Together.
Hold Position - used to be engagement range with 3-4 presets iirc
See above under Engagement Range and Auto Attack.
Leave Fleet - Hidden in a submenu with scuttle.
In Sins2 ‘Leave Fleet’ is hidden to same the extent as Sins1 (Advanced menu vs Tactics menu). But, in Sins2 you can bind a direct hotkey to it making it even easier but typically I just select the ship(s) and right click them into their own fleet – this also has the added advantage of keeping the removed ship(s) quickly accessible for whatever else you had planned for them to do.
It's hard to remember exactly what command a ship is following.
Press space bar (likely changing to ALT in the future) to see the command lines or read the tooltip (says exactly what its doing).
My support ships like my repair cruisers tend to end up a long way from the capital ships I want them watching over.
Select the repair ship(s), right click the capital ship(s) to follow. If the other capital ships are nearby he'll heal those too.
Extremely clumsy in Sins1, far far superior in Sins2. This addresses our number one complaint with Sins1 ship management.
Sins2 fleets allow you reinforce the fleet in a far easier way than the clumsy 'select a factory->build->rally' system in Sins1. Too many steps, too much micro if you want ships to rally to different fleets, confusing behavior about when and which fleet a ship entering a gravity well will join, etc.
Sins2 reinforcement allows to see the current composition, request ships to reinforce, auto researches ships that aren't unlocked yet, auto selects the best factories, handles the rallying and auto adding to the correct fleet. In Sins1 this was extremely frustrating to manage.
From my perspective the only regression is the loss of engagement ranges but I feel the new Fleet Reinforcement system adds much more to the game than the loss of engagement ranges takes away. Net win. In either case, engagement ranges may make a return.