To elaborate a little on the answer above👆: in WoT, projectiles have a thickness, width and height of one pixel. Therefore, in practice, hitting a "shell in a shell" would be extremely rare and only mislead the players, because there would be almost no precedents ... In short, no one needs it.
In WoT there is no such thing for a very simple reason - too small a chance and too vague result of such an event. Quite recently, a realistic projectile ricochet from armor was introduced into the game, so I still have not seen that this would somehow affect the game. Only in YouTube, in the guides, you can find rare cases that a projectile ricocheting caused any damage to a car parked nearby. Such cases are vanishingly rare, because the meeting of shells and bullets will simply be invisible and will not affect the game mechanics in any way. Unless the misunderstanding of the players will only increase "where my shell disappeared, I should have hit", and even then not much.