Add a limit to the number of active squadrons that can be deployed at once before degrading fighter performance. Perhaps a max of 10-12? squadrons deployed at once then start applying penalties to fighter performance as the number increase.
I wonder if making fighters collide with each other would prevent them from swarming at the volume where fighter blob becomes an issue.
(I vaguely suspect the main side effect would be killing CPU when fighter AI has to take collision avoidance into account)
I suppose at the very least if they can't shoot while stacked, that should be close enough.
While I agree with the overall idea of reducing spamming effectiveness and think that
is the appropriate place to target balance changes to fighters, the above implementations have more potential problems than I think is worth the effort.
1) In the case of global wing limiters: similar to the CR mechanic (A historically polarizing update to the community) these types of mechanics run the risk of feeling like gimmicks purely for the sake of game play balance. You can explain them away with lore or WWII examples possibly, but I think its going to feel weird to the player anyway because its a relatively arbitrary global limiter.
2) In the case of stacked fighter collisions and stuff like that, there is the performance issue with collision avoidance and the addition of a new layer of balance to consider. This balance layer scales exponentially rather than linearly. What I mean by that is there will be a sweet spot of fighter numbers that maintain optimal effectiveness, but once the threshold is crossed suddenly the effectiveness completely tanks. Not a good feeling for the player in my opinion.
3) You have to effectively and intuitively explain this information to the player. Just like how supplies per day UI can be confusing to new players, all players are going to see is that "as I get more fighters they get worse for some reason." You might assume a player would ask about it on the forum, but I believe the statistic iirc is around 6 players will feel the same way but only 1 out of those 6 will investigate on average. The others will likely just assume fighters are bad and not use them.
4) Spamming all fighters shouldn't be the obvious best strategy by any means, but I would caution against design changes that outright force or overly encourage certain play styles. It feels a little like railroading away from fighters on purpose just because they are strong now. Nothing is outright forced at the moment, it just so happens that a fighter strategy is optimal and so some players feel subjectively forced to use them in order to feel optimal. My advice is to dampen that feeling without railroading away from the fighter play style on purpose.
5) Finally, and arguably less important, there is modding to consider. The above proposed changes would at best require modders to work around them for fighter heavy mods, and at worst kill those types of mods altogether.
My proposed solution:
There's only so many ships that can fire on a single target, and even when they are together they have to watch out for friendly fire. Fighters have virtually infinite force concentration and no friendly fire. That's the main issue, besides AI ships not dealing with fighters especially well.
I personally think AI tweaks are the best route to take here. Instead of reducing fighter effectiveness when stacking or causing losses and performance hits by implementing fighter collisions, instead limit the number of wings that can be active on any one target (by hullsize). So fighters are no longer overly spammable on any one
target instead of just globally. This would sort of act as a soft limit, however, in that if a single carrier has more wings than the limit for a single ship, that is ok and won't cause a penalty,
but no other carriers will be able to send their wings against that same target or can be assigned to the same fighter strike order. Attempting to do so fails and gives a brief "you can't do that" sound effect. Actually, I've thought about it and that could grow frustrating if you needed a specific vessels' fighters to engage a specific target due to tactical necessity. Instead, new fighter strike orders override old orders but the soft limit prevents over-saturation as was the original intention. I think that tidies up that issue I hope.
(The way to teach new players this mechanic could be included in a simple popup the first time a player issues a fighter strike order on a "saturated" target.)
I think the idea of "target saturation" is more intuitive than seeing your fighters get weaker or completely ineffective when clumped. The same reasons (fighter coordination etc) apply and hullmods could reduce the number of active wings allowed on the ship for better fighter defense ship-to-ship.
It would help if there was some "general fighter behaviour" setting (for entire fleet or for individual ships — preferably the latter), where you could either pick force concentration or distributed presence.
This also makes the AI spread out fighters kind like the distributed idea above, and allows for fighter strikes (force projection) to be balanced more easily without worrying about the critical mass problem. If you can calculate exactly how many fighters of each type can actually strike at one time, then as long as PD can handle
that specific amount unless otherwise distracted (like by an enemy combat vessel or missile spam) fighters should theoretically feel like they are in a very good spot.
Rough example of wing limits off the top of my head:
Frigate: 3 wings
Destroyer: 5 wings
Cruiser: 8 wings
Capital: 12 wings