First of all sorry if this has allready been mentioned a gazillion times, but for now I just want to get this "annoyance" of my chest.
Coming from the homeworld series it was a delight to finally see a good sci fi RTS again and I do like sins... However I've probably been spoiled a bit in that regard. Homeworld gave us many options befitting of it's 3d setting (perhaps too many at times?), but less can do for sins even while still giving the players a more practical choice.
The annoyance so far is that... the options we do have... doesn't really seem to work that well. Fleet cohesion tight, normal or spread out? Seems kinda irrelevant... If you want the ships in wall and do the wrong thing... in they go in a bundle... Want to put a certain ship type in front? Sorry, can't do. The game has allready picked that... And so on and so on.
My suggestion to enable and bring in formations and fleets as a real aspect of the game consists of the following:
1: A "move as a formation" option, that forces every ship to stay in its place at all times, lets no ship move individually, while only regrouping when out of battle.
2: A sort of "fleet editor" gui that lets you do the following:
A: Lets you add and set rows of depth and height of the wall formations.
B: Lets you select ship classes to the row you want them in.
C: Lets you set distance between ships in each wall and between the walls.
Imagine the possibilities with this. You could make your own formations like this:
Support Long Range
Tanky Battleship. Long Range Empty row Empty Row Empty Row Carrier
Support Long range
Or:
Heavy Cruiser
Heavy Cruiser Support Longrange Carrier
Heavy Cruiser
For simplicity I kept the options down somewhat, in that you cannot pick, how each individual row of wall formation will end up if you mix different classes, but it would be possible to add those options too.
From a users perspective I could it imagine it looking a bit like this:
1: A formation button when grouping a fleet, this opens a new "page" on the fleet gui part.
2: This new page has 4 buttons.
A: A select ship class to add to a "row".
B: A button to set height of the "row". Ie. 4 ships high.
C: A button to add a new "row".
D: A button to select whether individual ships in that "row" should be tight, normal or wide.
3: The regular fleet tightness button would instead set distance between the "rows" of wall formations.
4: An option to let the game sort the fleet automaticall for those who want that or maybe this should be the standard thing.
Granted. I don't know if any of this is possible, impossible or if it would just be too expensive in development money and maybe my occassional annoyance at the lack of options in this department in the existing game would never be enough to justify this...
However... Personally? I think it would add alot of tactical depth to the game and I'm pretty sure they could lure me to buy something that added this to the game. 
