Lannan was Lannan. He's not an ace, he's not a #5. He's a solid #3 on a winning team and that's what we're trying to build.
He's much better than a #3 pitcher. You do realize that there are 30 MLB teams? That would put him approximately between 61 and 90, if you're ranking pitchers, if he were a #3. Of course, this is an inexact ranking because some teams will have several really good pitchers, San Fran, for example, and they'd have #2 pitcher who's better than other teams #1. It's inexact but it's a close approximation of what a #3 pitcher is. Again, he's much better than that.
He's a #1 pitcher, at worst a high #2, because he's among the top 30 pitchers in baseball. He's just not an ace but most teams don't have aces, including most good teams. There are just a handful of true aces in baseball.