All of the cuts from guards use a long cutting arc and a 'tell' as the cut starts. This would be terrible form in reality, but it is very necessary in games.
Of course not all real guards are for delivering the shortest cuts, though Vom Tag, High Tag and Olber do offer the option for relatively fast direct cuts.
Zornhut is a guard which is even more 'wound up' for a Zornhau or Oberhau cut, with the sword resting on the back and the weight brought back over the trailing leg. Very obvious telegraphing of the likely attack, but one that is very powerful when the body mechanics are correctly aligned with the cut. It is also an effective guard, even though the sword is completely behind the fighter as defensive cuts can be thrown with power before winding from the resulting bind, or cutting around. (I like schrankhut, and nebenhut as defensive guards for the same reason - they offer stop cuts or clearing cuts which are very strong, without exposing the hands and arms to easy fast hits - many of the guards used have the arms ahead of the body, which given the weak arm defence of many enemies is more of a problem than the angle which the sword is animated to/from.)
It wouldn't be feasible to have a game where the direct cuts are thrown at realistic speeds - my direct zornhau often beat an opponent in the real world, when I get the mechanics right and have no tell, and in a game where muscle memory isn't a thing and commands have to pass through visual and controller manipulation before a response is possible, it would be extremely difficult to even see what was going on. (I see maybe 2-3 frames between guard and strike in video footage of sparring if there is no slow motion shooting).