It's interesting to see how the warship designs start off with a different sort of 'balance' from the conventional start, especially with limited scientist admin meaning you can't just rush MP drive tech in 10 years. Starting off with the 25cm railguns is certainly different!
I'm curious, Steve, if you've ever considered building your colony ships as hybrid colonist transport + cargo hold vessels that can transport their own infrastructure (200 or 250 per million, I would suppose). These would be pretty massive ships which feels very Warhammer to me.
Gothic class Cruiser
I admit, I'm a little offended that this isn't the Lunar class. Gothics are lance boats, dammit!
That said, 60,000 tons... really liking the upscaled warship sizes in this one!
Will be interesting to see how the Jotun develop. You did start with 10 NPRs, but from the sound of it the Jotun are probably a minor race and so probably not much use as allies unless the trade income is worth it? So probably a better target for exterminatus. That said, between the Necron threat and yet-to-appear threats from the Dark Eldar, Tyranid, and Chaos factions, will the Imperium have the time and resources to carry out such a holy mission?