You want to know why all gauges are the same units?
In the MA, you can fly any plane you want at any time.
Can you imaging the Cluster F@ck of people trying to communicate between systems? The guy in the German plane tells his wingman in the US plane, "I'm at 25KM altitude, where are you?" US response, "I'm at 25,000 feet, how high is that compared to you?"
Or the mega whines from side to side...
"No way you could catch me, I was going 400KMH!"
"Sure I could, I was going 375MPH"
WHAAA!!!!!
The list could go an and on.