There's zero indication that the accuracy of a macro weapon at 50% past it's effective range against a target with 8g acceleration and Gravimetric Engine Calculations is still 25% percent, and I doubt that the OP will model space battles at that level of detail anyway. The point of my design is long-range harassment with thin defences against those attacks that make it through. You can like that or dislike it, that's up to you, it's certainly a very specialised design, and in large part because we have our station to act as a strong point. It's certainly not meant as the only design for a destroyer we'll ever field, but I think in what it does do it's adequately statted.
Buddy, I'm a veteran of Rogue Trader and I've played Battlefleet Gothic in the past, I know how naval combat in 40K functions.
The mobility of a voidship
only matters in its defense if you can permanently stay out of targeting range (Which is twice the battery's effective range, shooting past your effective range is just a modest penalty to your roll), because shots don't
slow down in space. They keep going until they hit something or disperse too much to matter, the increased difficulty past effective range is because you need to lead your shots better.
But let's put that together for now.
Let's take a bog standard rando, untrained Imperial Civilian, skill 30, and have them fire a macroweapon at Long Range. They've
still got a 20% chance of hitting you.
Now, you
can nudge those odds, because Evasive Maneuvers are a thing (Just as teamwork, and Actually Being Trained For Your Job can on the part of the gunner)--and for
That, your mobility
does matter... But it comes at a cost--namely, that being
that much harder to predict makes it
that much harder for your gunnery crews to do the same. You can't exactly tell your gunnery crews to compensate for random maneuvers without them no longer being random (And thus, no different from standard operations), and being a degree off in naval combat means you just completely whiffed your barrage.
I don't even need to draw into Game Mechanics to understand that. Because
that's basic physics. A direct fire weapon is not going to be just as easy to shoot when your firing surface is constantly moving in ways you have no power over.
You want to know what
doesn't care about Evasive Maneuvers? Torpedoes--which once fired will continue to move and track their target until they run out of fuel or are destroyed. Nova Cannons which just need to get In The Same Country as the target. Strike Craft which operate entirely independently once launched.
Ordnance, in other words. Indirect Fire in simpler terms.
If you want to do dodgy, skirmish builds that count on never taking a hit, you load ordnance, fire from outside effective range, and proceed to book it, doing Evasive Maneuvers until you're ready to do another attack run. You don't do a direct, precision laser boat that will explode if it ever slows down to line up a barrage.
