Why would you want this for "real" ? Unless the driver mode is fixed. Who want to micro manage the angle of all of their tank manualy ? Why would the tanks AI wouldn't turn their body sideway when needed automaticaly ?
If it's done automatically, then it would only be body dependent. Some body would have better mean deviating armor then others. Pushing the simulation up to simulating each single angle when anyway we randomly generate that angle would be useless. At the end, it would only be a new armor set in % of damage instead of fixed value.
It wouldnt be hard at all to implement but for which goal ? Everywhere you want a armor in %, simply increase the HP by the same amount.