Ultimately, yes. You're right. Bryan Leonard responded in a post shortly after I joined pregame and said, "Ultimately, we're guessing." Obviously the trick is to get more information. And when the info or stats you value point to one side with enough weight, you go with it.
All of this stuff at pregame is just guesswork. How many guys, myself included, post opinions as if they actually know what's going to happen? You just hope to find someone who will tell you the truth, own up to his/her shortcomings, and give you some realistic idea about their leans because in the end that's all they are: leans.