I don’t know if this has been mentioned before, but a thought just struck me. On the level Come and Take your Medicine (Terminal 1), Durandal says:
“It must seem peculiar, fighting the S'pht when they are whom you seek to free. You should be told that they deliberately fight poorly, that they are constantly resisting their slavers.“
Now of course, the immediate reaction might be, “Are you sure about that?” Even on this level, the S’pht aren’t pushovers, and they sure don’t seem to be going easy. But then I thought about the fast-firing S’pht on the level “Where Some Rarely Go”.
Sam Morris on the Story page asks why these S’pht are so much tougher than all the rest of the S’pht in the games. Perhaps each S’pht has the ability to fight like this, it’s simply that they are holding back during their fights with the player. Maybe the experiments that were being conducted on the S’pht at Perimeter Garrison 7A removed whatever mental inhibitions they had to this kind of fighting.
While there are a few holes in this theory (like why don’t the Rampant S’pht fight like this, or the S’pht in the first game before you ally with Durandal), but overall, I think it’s a possibility, unless I’ve missed some evidence that would contradict it. Otherwise, I’d love to know what you guys think!