As you can imagine, such an endeavour necessarily involves a certain number of assumptions to be made, as such I have generated ship DPS tables to reflect the 'optimal' firing arcs of each ship, i.e. Imperials are always broadside, the majority of Tau are prow firing.
Exceptions exist where no clear optimal firing arc exists, and I have tried to accommodate these scenarios, such as Demiurg ships and Ork ships (though this often reveals the optimal firing arc).
Finally ordinance, this presents an issue, however I have tried to treat these consistently, therefore these are treated as 100% accuracy (not realistic I know), therefore many of these tables represent 'ideal' scenarios, but at least all ships are compared under similar 'ideal' conditions. However it does mean direct comparison between hangers and conventional weapons based ships shouldn't be taken on face value!
Therefore moving on to some observations I've made, it looks like Chaos ships (in a straight up brawl) win point for point, therefore for Imperials to turn the tables, torpedoes and Nova's are a necessity, especially if the chaos player takes advantage of the substantial difference in long range DPS between these races.
As previously pointed out, the Murder is a weird outlier, as in it's terrible, I've looked at this one several times trying to figure out if I'd done something wrong, but no it is just pointless, the only scenario it beats the slaughter or carnage is at 18k with it's prow lance, but this means you're wasting all of your broadsides, which are optimal at 9/13.5k.
Tau, whilst on the face of things having some absurd DPS numbers, breaking down these numbers, a large amount of this is based in ordinance, indicating that Tau have a high delta with minor sustained DPS (railguns and ion cannons pretty much tickle other ships for the cost of the ships they are on).
The changes to Mechanicus I think will make a large difference in their effectiveness, and I think this is a welcome change to differentiate them from Imperials, making them a more effective at longer range.
I hope people find these sheets useful!