It's "1-shot" radius is 1.01; and grens have a horribly tendency to 'blob' together in cover.
Regardless, let's image a "best case" scenario, where the shell only lands perfectly on one model. The squad is now at 3 models. However, the 2nd closest model was likely in the "mid" damage range, so it took 56 damage, and the other 2 models were likely in the "far" damage range, so they took. 32.
The AOE damage is 1,0.25,0.15 (near, mid far).
The AOE distance (damage done in those ranges) is 0.25,1.1,6 (near mid far)
Therefor its total AOE damage is...
.240 dmg at 0.25 near
.60 dmg at 1.1 mid
.36 dmg at 6 far
Damage is even less for vet 3 grenadiers, the possibility for one shots is suppose (and is) to be rare(This also applies to the kv2 as they share the same AOE stats)
Ill just show the brummbars aoe anyway
AOE damage is 1,0.35,0.2 (near,mid,far)
AOE distance is 0.625,1.25,6 (near,mid,far)
.160 dmg at 0.625
.56 dmg at 1.25
.32 dmg at 6
Its interesting the brummbar has a higher near OHK radios and a slighting better but less damage mid aeo. Edit: this is most likely due to the brummbar having lower range and fighting Allie squads which tend to have a higher modal count.