the animocity is because aces high models the period of the air war when the luftwaffe got its bellybutton kicked, and the german industry was making toejamty airplanes compared to those being produced in GB.
the luftwaffe kicked bellybutton in 1039-1942 but after that it sucked. the me109 G sucked ass, the fw-190 stagnated, and the me262 was too late. all the while the clipped wing spitfires and mossies were rolling off the lines in GB relatively unhindered by bombing.
the emphasis of aces high on the late war favors RAF fans when they get their rides, because the RAF planes WERE better. Why? Because they didnt have supply problems in the late war (wolf packs were long gone) because of hitlers stupid prosecution of the war.
the german fans probably have the desire to mix it up like the brits can in urning fights etcera but their planes just dont allow those types of tactics if success is desired.
i can speak from personal experience that the animosity can come from friendlies, not teammates. if you have flown both the 109-g10 and the spitfire, you will know that the g10 is the better airplane, but certainly not the easier of the 2 to geta kill in. when you are in a g10 and you work a pony down to the deck after a long engagement then have a person with easy to hit with cannon in an agile plane (ie spitfire) swoop in and take the kill, this can lead to alot of frustration.
the hispano cannon is probably the last point of contention. i think the way that ammo has been modeled as a combined mix gives hispano cannon a bit of an edge in aces high vs the mauser. the germans had access to the hispano design when they captured france. i believe if it had been as superior as it is in aces high in hitting power (not ballistics, i think the ballistics are spot on) the germans would have adopted it.
the problem with the damage model lies in the hit points for components damage model, where the hispano takes off considerable more "hit points"... well from a mathematical standpoint, calculating strict KE and chemical energy amounts, it should, but in terms of killing soft targets like airplanes i dont think ammo works like that.. in reality an AP shell taht hit a wing in a non critical location would do no nearly no damage.... not so in aces high