AoE accuracy being above 1 at all times (even after considering received accuracy modifiers like cover or veterancy or retreat modifiers etc.) just means that EVERYTHING in the AoE will take the damage, which maybe should be the case for something like flame damage, but not necessarily for something like grenades (at least from a realism standpoint). disregarding realism, 100% aoe accuracy would probably make every splash weapon (basically all indirect fire weapons and all vehicle weapons apart from MGs) a lot stronger and might make units that are already perceived as too strong even stronger (i.e. mortars, arty, tanks etc.).
Well, at the far range most are just doing 0.25*dmg. If theyir accuracy were increased to >1, more infantry would be reliably hit. They could then decrease the 0.25 multiplier to something like 0.15 (pulled out of my hat, though 0.25/1.4 would be around 0.18 I think), which would mean that the overall average damage would be the same but those weapons would simply be less random, which in turn would be good for gameplay.
Since those values are weapon-specific they could also only change the values for grenades. After all those cost munitions (requ. resources) and have to be manually aimed (requ. skill) so making them as random as they seem to be isn't really a good thing.
Mortars and tanks could either stay the same or have their damage multiplier decreased as well.
However, I agree that some randomness probably portraits the fragmentation effect of anti-personnel weapons better than flat damage (would be for high explosives maybe). However, I've always prefered consistent gameplay over realism and so at least in the case of grenades I'd really prefer it.
But I guess now we're very far off topic. It'd still be great getting confirmation about how explosions work and if the stug/scoutcar/maybe other weapons are bugged.
Skipping through the vehicle patch and checking on CoH2stats shows that none of the vehicles seem to have had their AoE changed to the patch values (might have missed some, didn't check all). So I guess all of those changes listed were to the (not on CoH2stats displayed) radius.