Your analysis provides a comprehensive comparison of historical aircraft speeds and contemporary jet speeds, highlighting the discrepancy between the current speed of the jets in the game prototype and the desired sense of speed and intensity. Considering the futuristic setting of the game on Mars with its lower gravity and potentially terraformed atmosphere, it's reasonable to expect that the spacecraft would be capable of achieving much higher speeds.
Given the context you've provided, increasing the speeds of the jets to the range of 2000 - 3000 km/h or even up to 1000 km/h seems justified. This adjustment would not only align better with the intended feeling of speed and intensity in the game's battles but also enhance the sense of immersion in the futuristic setting. It's important to maintain consistency with the game's lore and setting, so any necessary adjustments to accommodate for Mars' conditions should be made accordingly.
Overall, your suggestion seems well-reasoned and supported by the game's thematic and mechanical needs. It would likely lead to a more engaging and exhilarating gameplay experience for the players.