40k scale is big. Longer ranges, larger vessels by general.
EaW is a great game, but it would really need a zoom in.
To put it into perspective, the KOTOR corvette that rammed and pushed an ISD into another in Rogue One is the size of the regular macrocannon fire used by Imperial ships.
The game also is not really up to scale. It is a representation of a tabletop game, and thus there are old things that clog it up like 2d and "stylized" ranges and sizes. The range is also practical, since 5-10km ships shooting at each other from hundreds of thousands of kilometers would not be that spectacular.
Big fleet engagements can begin at AU ranges. That is the range between the Sun and Earth, though I assume it does decrease accuracy. But when shooting at an ork fleet or nid swarm, you are bound to hit something.
But I do agree it could use some improvements, like escorts coming in squads like the infantry did in DoW games.
And 40k does not even really have a canon size, it is like the case of the SSD with 9km to 19km scales.
Cruisers have been stated by official sources to be anything between 3km to 9km, with battleships going from 2km to 6km to 8km to 16km.
It is all over the place, so the game uses the model scale for BFG board game.
This comes down to SW being a space opera, where the Big Bad needs a Big Bad Ship that just totally dwarves everything else. No offense to Squats.
40k is more like a warsploitation where vessels are not that required to play into the evil overlord's stronghold role by default. It does happens at times, but not as much overboard as with SW.
Usually 40k "boss ships" are not as much bigger than their line ships, with Glorianas being 20km+ so at best twice as long as a battleship.
Even though they ARE very powerful, enough to wipe out planets or fleets on their own, but their size is not so great compared to the rest of the fleet, akin in style to the Scimitar of the Star Trek movie. It could kill a planet but it was not gargantuan when compared to the average Romulan vessel.
GW does not allow non 40k stuff in it. Plus, most other sci-fi would be stuck at escort only fleets save for a flagship.
If you are looking for a similar game, Star Wars has Empire at War which is pretty similar, with more 4x and ground options but less actual ship tactics and abilites.
Mechanicus male and female doesn't matter, its all metal anyway and they wear robes.
SM: Girly marines would trigger the manosphere, but if they were made super pretty it would trigger sjws too.
IN: There are admiral portraits for you, but for the ships they would need another VA to do them, and than they would need to match the voice to the portrait, or you would get male admirals with female voicelines or female ones with male voicelines if it was just randomised.
Though tumblr would like that...
Though you can't blame that admiral girl for that, its not like Glorianas are common so she had no idea what one could do.
Pluis Girlyman's waifu is the eldar boss and she trolls you real hard.
There is a lot of GW sources or conflicting sources, but generally these are mostly used:
Escort: 1-2km, though there was 30km Cobra in an old novel.
Light Cruisers: Mostly no info, but 3-4 km sounds accurate.
Cruisers/BattleC/HeavyC: 3-4-5-6-7-8 kms are all not uncommon.
Grand Cruiser: 7-13 km had been mentioned somewhere.
Battleship: 6-8-12-16km, but there has been a "Smaller than 2km hiveship" in an old novel.
Battlebarges are usually battleship sized, and Strike Cruiser maybe between LC and Cruisers.
Transports are the weirdest bunch, with 1km to 3km to 6km to 15km to 60km for the biggest conveyors.
Basically it is all over the place.