saves:
I can't load the saves (since it requires a PW)...but I have anyways no idea about multiplayer.
historically/immersion:
I understand the complain, but completely removing a CU from the map everytime it loses too many men would result in too thin manned lines pretty fast i guess, since you can't create new formations from scratch. And looking at history many completely "dismanned" formations have been rebuild.
If you inflict 100% losses after a rout many of this losses may have been occured after the battle (leaving equipment behind) so you basically have not "destroyed" that stuff but it was rather left behind to escape/save the CUs officers/leaders (further see "the math").
the manual:
Overall the battle result as far as I have understood is mostly impacted by odds, kind of formations fighting and supply status (isolated/pathing etc.). Therefore the game doesn't only care about how many Ground Elements got destroyed while/after fighting, this ratio is only used as one part of determination wether a CU shatters.
Let's assume the attacker always wins, the defender will always retreat and other specific circumstances will make it a shatter/surrender, if those specific circumstances are not met it can only be converted into a rout, not a shatter/surrender.
Living Manual 1.18 p.70 wrote:
- If the defender is in a hex that was isolated at the start of the turn (23.12) and is forced to retreat they may retreat normally if a path exists or surrender. They will always surrender if they have no valid retreat path;
- If the defender had no valid retreat path (but was not isolated at the start of the turn), then the retreat will become a rout with much higher losses;
- If the defender is badly beaten, has low morale or [low] experience, poorly led or is an infantry unit facing motorized attackers, it is possible [additional RNG involved I guess] that a retreat result will see the unit shatter and be destroyed instead of retreating. In these circumstances, even if the unit retreats normally it may also take much heavier losses.
In the third part I interpret the circumstances as ANDs, since dedicated ORs are named itself.
the math:
Read on 23.10.2. Battle Losses (Living Manual 1.18 p.424f).
No all dead elements are actually 100% dead men, some men survive(wounded)/are captured instead. So the indication of losing 100% isn't 100% correct as far as I'd interpret this.