Hassan didn't even try to face the Roman army in open battle - he just got really lucky and managed to destroy the Roman siege train, after which they pulled back. Once it's replaced, they'll be back with better rear area security and knowing not to underestimate him.
True, but the Germans would find it easier to interdicts any organised large-scale efforts to get supplies into Stalingrad if they control both banks upstream and downstream of the city. They might even resort to medieval methods and simply string chains and other barriers across the river to...
TV Tropes is one of the greatest time sinks ever devised. You originally go there to look up something specific, and the next thing you know, it's four hours later and you're frantically mashing the "Random" button like a hamster trying to get its next food pellet.
Other than shooting "NO MORE" into that wall in Arcadia. And being willing to use The Moment to commit double genocide on both the Time Lords and the Daleks in order to end the war.
While it might be possible - however unlikely - that Heraclius survived, another possibility is that like OTL's Constantine XI Palaiologos, his body simply wasn't recognised due to the lack of insignia on the plain armour he changed into.