Unfortunately Fugitive was slated to die so, to a degree, his actions in that final fight can't wholly be blamed on him, if that makes sense. I'm choosing to personally interpret it that he knew he was outmatched, but he made a brave last stand to the best of his ability rather than fleeing. (Though I don't think it would be cowardly to try to draw Upgrade into a more advantageous situation, predator values are different, and like I and previous comments have said, the writers intended to kill him, so Fugitive's choices inevitably forced him into that situation.) He was definitely wasted, he was great, and it feels so obvious that it would've been more interesting to keep him around until later in the movie as a foil and foe to Upgrade.