This is the same behaviour of salvaging fighters - which makes it difficult to salvage with them. There are a few changes that could be made that would greatly increase their use.
First off, when salvaging instead of having all fighters target the center of the target (this works for combat, but not for mining and salvaging) have them target in a similar fashion as the auto targeting salvage and mining turrets. Also, it would be of great help to have the fighters auto target - they're flown by pilots you hire after all! Perhaps if there was a Auto Target mode you can select with them so they'll seek out targets within their range - mining, salvage, and combat.
As things are now, I feel that fighters are broken and not worth any investment due to their cost and inability to function in a meaningful way. Hope my feedback helps!