In real units? We have no idea what any of the ship's dimensions are. Also it seems the planets and ships are not to scale, unless even the strikecraft are as big as today's aircraft carriers...

I disagree. You align a ship against a planet. You would see that he ships are much larger than they should be against a planet. Even against other ships, some ships are way bigger than the others. For example, the Kol against the Titans, I mean just looking at it, the Kol is roughly a quarter of the size of the titans. Even though it should dwarf it even more.

And given that the titan is pretty much nearing half the planet size, maybe a 1/3 of giant planets such as the gas giants, it is virtually impossible to build a ship that size. Even the death star isn't that big.

We do know some of the crew sizes on some of the ships.

The crew sizes for the titans will prolly be in the maneul as well.

The original Sins of a Solar Empire had the crews of each ship in the Manual (should be in your original SoaSE install directory). The Kol for example is given a crew of 2,500.

I dont think the supply points are meant to represent just the crew members (or a multiple of them), but all of the resources needed to maintain a ship.  Not all capital ships have the same complement.  The Rapture, for example, has 4000 souls on board.  And while the cobalt uses 5 supply, it only has 150 people while the Disciple only has 75 (4 supply).

These ships are highly advanced and there is likely a great amount automation to keep them running.

However, I do hope that there is an updated manual with lore for the new ships.

Full sized aircraft carriers may have that much or even into the 5-6000 range, but most non carrier combat ships do not have crews larger than 500. The largest non-aircraft carrier/Amphibious assault ship I can find is the Soviet built Kirov class at 700 some crew members.

Indeed it does, WWII Battleships had 1200-2000 men easily. But I was talking about the modern navies, and alas there are no battleships left, though some consider the Kirov to be a missile Battlecruiser. Smaller ships plus automated antiaircraft weapons and other computerized systems really reduced amount of crew needed, and I'm sure that Sins is the same way on an even larger scale.

Too be honest I think the Protev in the new intro really is too small. Looks more like an airplane scale than a frigate filled with supplies, troops, diplomats, etc etc needed to set up colonies.