How do we say french "CQFD" in english ? QED ? Sturm, you just demonstrate there is not point to search realistic rexplaination while there is mechanical programming reasons which imply bias.
(and i have seen nowhere the vanilla's pistol is a desert eagle, which seem weird to me because there is no point to use this in military theatre. If we want realism, in my opinion, xcom will use a FN P90 and his dedicated pistol FN Five-seveN. Why ? because it take time but we finally understand that a lighter but faster bullet is really more usefull than a heaviest slow one, like the .44 for example, well known but obsolete, and two weapon able to fire the same ammo is really practical).
But in 90's, theses weapons where new and not well known maybe that why vanilla's give weaponry out of date.
In my opinion, in a game we must search coherency more than realism
So come back to ths subject, external UFO damage for me seem change all the game. And I don't think it's for the better because if UFOs are in pieces and half the crew already dead or badly wounded, missions will become far too easy, no ?