So I thought about it for a little bit, and I determined that it is best to only star level cards that you WANT to draw attention to. For example, I start leveled my Pekka to level 2 because it's already a high-profile unit, and I want my opponent to focus attention on it. However I will not be star leveling my battle ram and my bats because I would rather give them a better chance to slip by unnoticed. Same goes for my ice spirit and my zap, because the less attention drawn to them, the less likely my opponent will remember that I just used them, making it less likely for them to take advantage of my cycle.
It's a subtle thing, but it could potentially have a large impact.