"the model of the atmosphere or the plane, but something seems awry, Especially with the 163."
No, its called thin air.
At high alts you cannot manouver like you do at lower altitudes, but if you have noticed, planes do travel at much faster speeds and accelerate rather slower than down below.
That is why planes like the 152 and p47 , who'se accel and top speed are fearsome above 25k are the premiere bozosphere fighters... while at the same time it makes the P-38 an excellent plane because it not only accels good but it suddenly becomes the best turner 'up there' thanks to its fowlers and its stability do to counter-rotating props...while still retaining its excellent climb rate, acceleration and having damn close top speed to the jug and enough to make a 152 have to extend for a good bit.