> I have a few qualms about some of the arrangements (for example, Earth City is at too slow of a tempo for my liking)

That’s the one that bothered me a bit too. Weirdly low energy. Did Jeb Bush arrange it?

I don’t know what scene(s) they used it for. It’s possible adaptation is to blame rather than anything musical.

Also, as part of this effort I learned this piece was originally written for the game’s May 2003 E3 demo, meaning folks heard Marty’s new themes for the Chief and the Covenant a year and a half before the game came out.