I'm not sure what you meant by the last comment, Keith.
I will breakdown my grievance with this thought process, so you don't think I'm trying to be condescending (which you are), but rather create an actual discussion. If Michael Clayton had a more coherent narrative and an actual theme (instead of the handful that are presented to us at any given point), having something like wild horses as symbolism that is open to different interpretations would be okay. Because there would be a frame of reference; it would fit within the context of the story. We could go, "Hey, this movie is about this, so the horses might be about this. Or that." Or any number of things.
Whereas if a filmmaker of Kubrick's talent gives us symbolism that is ambiguous, he has given us a theme or a point of reference - even if that particular object or sequence could mean many things. But it means something within the movie. In the end, he or she has put that symbol in his film for a purpose. Symbolism without purpose is just abstract crap. I'm not knocking interpretive art, but I am knocking ostentatious writing thinly veiled as symbolism.
So who is at fault here? Is it half-baked symbolism without purpose, just a coincidental plot device or something more? I think it all boils down to mediocre writing in this particular discussion. Let's say, for the sake of discussion, that the wild horses are meant to be interpreted as something more than just a coincidental plot device, then I argue that the script doesn't allow it to be meaningful. Michael Clayton is not 2001.