The reason why I am saying that the +50% TA/+40% Vet3 does onthing because storms will never be facing units like rangers, commandos, shocks in 1v1 fights because these squads both out tank and out dps them at the mp40 stormtroopers preferred range. So +50%/+40% is pointless to the out come of those fights.
It is never pointless, only in head-on 1v1 fights that will rarely occur (never if the player with Stormtroopers is wise enough). In all other circumstances where Stormtroopers are ambushing these squads, or shooting them up on retreat, or fighting wounded ones, both those accuracy bonuses are going to matter. Vet 3 Stormtroopers have a good chance to win vs vet 3 Commandos, anyway.
What the whole lowering accuracy does is increase the max dps they do which helps vs squad with 1 or more target size like unveted infantry and support crew.
But that is a non-issue? Storms already absolutely destroy unvetted or otherwise low RA infantry and support weapon crews in mere seconds. Generally without taking a single casualty. They don't need extra DPS against those targets?
My main point is that at vet0 the dps difference between storms and pg's are 20.1 % but at vet 3 it is only 3.3% (both in stormtroopers favor), This is not much and pg's have considerably better dps at all other ranges. Which mean vet3 storms aren't really better but actually a lot worse.
But this completely disregards the Stormtroopers' camouflage which allows them to ambush other squads under favourable circumstances, and also allows them to not take any fire from other long range sources before opening up, unlike PGrens. Their ambush role is sufficiently different and powerful to distinguish them from PGrens. If you want brute force infantry that can hold their ground against charging assault units or help assault themselves, pick PGrens. If you want to wipe support weapons, line infantry or pick off wounded squads, pick Stormtroopers. Both are excellent in their own roles.
For the other targets it's just overkill acc.
That isn't really true, vet 3 Riflemen have 0.64 RA and vet 3 Infantry Sections (in cover) have 0.62 RA. Assault Engineers at 0.64. Sappers at 0.59. Guards at 0.64. Pathfinders and Paratroopers at 0.71.
With the accuracy overkill starting around 0.6 and up, there are plenty of targets Storms can shred that they won't have overkill (from
both the vet bonus and the Tactical Assault bonus) against or at least nothing beyond a mere 5-10%.
And that's even without regarding the moving accuracy penalty. If we include that, assuming I'm doing all these calculations correctly, only 0.8 or larger targets provide overkill accuracy. Very few squads in the late game (bar newly built ones) have such a high target size.
What's also disregarded here is that both bonuses help against any target when said target is retreating (additional 0.4 received accuracy multiplier), as one of the major roles of Stormtroopers is hiding/operating behind enemy lines and picking off retreating squads.