@AWKM
Ah, good to know there's still stuff coming out gunwise, hopefully one of those gun will be the famous junker-sized heavy gun? (I can always hold out hope <3)
I'm not too familiar with firing the heavy flak myself, but from what I've heard my gunner say it feels like both bullets don't go to the same spot, or at least don't originate from the same spot (though this may in fact just be because of slight ship movement in between shots).
Now back to the meta of the guns. While I agree making drastic changes with new guns just on the doorstep isn't the best idea, I do have to point a few things out.
With guns not being so much a rock-paper-scissors as they are a choice of tactics (none of the guns can directly counter each other, it's just not designed that way) adding new guns will open up more tactical options, and possibly invalidate old ones in some of their current roles if some of the new guns are clearly superior in that role to current ones.
However! This will only increase, not decrease the amount of guns competing for a certain firing arc on the ship. All of the guns that are currently being outclassed for a certain role (whether disabler or armour piercer or w/ever) at a certain range, will STILL be outclassed if you add in more guns, they won't suddenly become a viable option.
With all the guns competing for their spots on a ship they MUST have a clear role and function, even if that function is: average at most things. Currently we have 2 guns (artemis and mercury) competing for the role of long range disabler, with the mercury both being better at disabling AND having the additional function of piercing damage (which you want to have because there's plenty of options for explosive damage).
Let's say you add another (long range) armour piercer into the game, which is better at the mercury at piercing armour, but doesn't do a good job at disabling ships (it's full piercing damage, for example). The choice now becomes: do I want the mercury for both piercing and disabling, but a bit less piercing than I could have, or do I want the full damage piercing gun?
Now let's say you add another (long range) disabler into the game, which is better at the mercury at disabling components (yeah, OP, I know, but follow with me here). The choice now becomes: do I want the mercury for piercing armour and disabling, but less disabling than I could have, or do I want the full disabling gun?
If the new gun is better at both then there isn't any choice, you take the new gun, period.
As you may notice, in ALL of those cases there is no reason to pick the artemis. It's only other attribute is it's explosive damage, which you can get alot more of elsewhere, thus it isn't in a viable position for any slot *unless* it's firing arc allows you to shoot from that slot when you otherwise couldn't (and for the vast majority of ships that's not an issue anyway, only the Spire comes to mind) That wide firing arc is just too ship-specific of a feature to be considered a viable role, when every other gun can be part of a build in most positions with a bit of creative tactics.
Let's not even get started on the banshee if you add in another long-range fire-starter that's better at starting fires at long range. What does it's niche become then, it's explosive damage? Most everything with explosive damage has decent range on it(and a ton more damage).
The point is that adding more guns competing for roles (unless all of the guns added are very niche) won't in any way solve the current problems. At best it remains at the status quo with only empty gaps being filled in (like a medium piercing gun) but at worst the new guns are either useless or outclass one or more of the other guns in their role as described above. Guns that are currently useless will remain useless regardless, and as such you can probably get away with fixing those sooner rather than later.
Edit:
I just realized that if you DID add in a medium piercing gun which has the kind of range and accuracy of the mercury then it *might* be viable to replace the usual mercury slots with artemis slots(on a spire/galleon), to have a very long-range damage-disabling build, though I would still argue at most practical ranges (e.g. there's clouds in the way now, alot of them in fact) the light flak or scylla with lesmok rounds would outperform it when it comes to destroying ships, and the mercury would still out perform it for disabling them.