Well it's not a bug then. It just doesn't know which units have Javelins vs Bows vs Commanders who are going to cast spells that require high precision.

I think it has been mentioned a few times before, that Aim needs it's targeting fixed, the same as BoW needs it's casting fixed.

Right now it's less than optimal, but if you know how it works you can make it as effective as it can be (since it's a very small AOE)