I sort by maintenance cost in the ship/bases screen to help group my ship designs.
Sorting isn't really the problem. For example, if you select "Fleet X" by pressing the F key, when you hover over one of the ships (lower left window) it will say the name of the ship not the design. The name doesn't tell me anything that I need to know. You must click the ship to see what class it is, then click the back button to get back to the fleet, then click another ship to see it's class, and so on. Needless to say this method is tedious even with the smallest of fleets.
We can use the ships and bases screen but this comes with it's own unnecessary complications. You open the oddly undersized screen and rather than a nice selection of easily recognizable icons, you are presented with a pull down menu which happens to have miles of space around it. This space could have been used for those nice icons but instead we get the lonely pull down menu. With that out of the way it's time to finally identify what design and revision each of the ships in Fleet X have. Rather than simply sorting by Fleet and looking at the name you have to click each ship, then look at the window in the lower right, click the next ship, look at the window, and so on. None of this would be necessary if the ships names were "design name + revision + production number". All of my destroyers in my current game were named this way by the AI and I much prefer this over the unique names all my cruisers have. I suppose if I were smart like Fredo I would memorize the maintenance costs of all my ships but with designs often costing the same and various revisions of those designs hovering around the same cost, lets just say I have no desire to count the fishes.
Lets move on to the UI in general now. Just kidding. Perhaps another day.