Yeah, it really irritated me that Mansell only did two tracks, given how much they hyped his participation (Crysis 2 did a similar thing with Hans Zimmer). It's even worse than what Crysis 2 pulled because Mansell's tracks are pretty much the only ones that have any sort of staying power, although Das Malefitz is a pretty catchy track.
At least Hans Zimmer wrote themes that the other composers ended up using. Mansell's track-and-a-half weren't picked up in the rest of the score.
(Though I would have said that his were the ones with the least
staying power - I much preferred Sam Hulick's work, and the other composers at least worked in a similar style.)