Are you putting aircraft into an Army meta unit? Because yeah apparently they won't do much then. I don't know first hand as I don't put air with ground forces into an Army. They get too easily shot down for potentially no gain if you do that. I put them into their own Ctrl groups and call them in when I want to, seems to work well. Though sometimes they don't really focus fire on the unit you want, especially fighters anyway.

It won't be your computer. But I know what you mean. I swear when I am playing other humans that their fighters hit what they want and hurt me, but when I try the same it rarely pays off...some psychological stuff happening there me thinks

I think I've found kind of a work around to this problem. If this is a problem for other people that is. Essentially do what the AI does, plot attack runs by using move command. if they are in range they will attack anyway. This way they take less defensive fire and always attack the enemies and structures in its path. Which they attack will be based on the inherent targeting priority. Which seems to be resource collectors.