You might think so, but you'd be wrong. Last week we had two distinct fights against other destroyer gangs (both outnumbered us and had more firepower than us) and yet beat both handily because we focused fire and were disciplined while they spread around their DPS. Yes targets die quickly, but that's why you have secondaries and tertiaries. Maybe the entire gang doesn't get on each individual target, but at any one point in time all your dps is focused on a single target. At no point in either circumstance should people be idle, but with focused fire you'll be taking down targets faster.
If you get to a point where calling primaries is no longer feasible (this point is larger than 20v20) then the solution is to have everyone sort by name and go down the list, not to spread dps. Spread DPS is basically never a good idea, unless you significantly outnumber an enemy gang and just want to grab as many of them as possible.
Again, was just referring to glass cannons in not-tiny engagements (5vs5 ofc it's better to focus fire because it's much easier to find the primary once called and because there isn't so much 'overkill' (as there would be with 20 destroyers all shooting 1 destroyer.) 10v10 is probably about where the two methods achieve similar results.
It'd be a fun theory to test with identical (not ridiculously overtanked, because then we're not flying glass cannons anymore) fits. If you can pop 10 separate called primaries in the ~ 35 seconds (fair estimate?) it takes a thrasher to kill another thrasher (not to mention that the ewar gets automatically spread perfectly as well with my method,) I'll eat my hat.
That's the thing though, I have tested it, I've tested it for close to 6 years now. Spreading DPS is
never a good thing. You either call primaries or you have everyone sort their overview the same way and go down the list. Spreading DPS is never a better solution to either of these tactics. There isn't overkill or wasted DPS, there's just moving onto the secondary after the primary dies.
The problem is that you're not accounting for the lost DPS when primaries die compared to split DPS. Think about this example...
Lets assume you have a perfectly equal 10v10 fight. Lets say that each individual can kill each other individual in 10 seconds (This isn't a realistic number, but it rounds nicely).
Now, team A calls primaries, team B splits damage.
Now, ignoring the lost DPS from people dying, both fleets could fully wipe out the other after 10 seconds, so yes, they're equal.
When looking at losing DPS though it looks like this.
0s - A has 10, B has 10
1s - A has 10, B has 9
2s - A has 10, B has 8
3s - A has 10, B has 7
etc etc
In the end, after 10 seconds B has 0 pilots and A still has their full 10 (with varying degrees of damage taken).
Looking at averaged kills over time is faulty because it completely ignores the biggest reason you want to focus fire to begin with, the faster each individual ship goes down the less effective the enemy gang is.
You're far better off killing a ship a second than 10 ships every 10 seconds.
The only shortcoming with focused fire is the possibility of people running out of targets and not having a primary to shoot. The thing is, there's an easy solution to that in sorting alphabetically and going down the list. Even hypothetically if the person just decides to shoot randomly you'll end up with spread DPS. Spread DPS is the absolute worst-case degradation of focused fire, defaulting to it just because someone might goof up and end up doing it accidentally(and yes, in this case not following primaries/directions is goofing up) doesn't make any sense.