As related to a previous question I asked I am planning to play as a Broodmaster. I will need to distribute feats between my Eidolons, but I can't decide whether it would be more effective to give all feats to one Eidolon or if it would be wiser to divide the feats between Eidolons.
It will mostly depend on what feats you are planning to give them.
For example, you can increase the damage per round by giving both of your eidolons Power Attack and Improved Natural Attack, but you would give up on feat-intensive builds such as Cleave and Vital Strike.
It's difficult to give you a more precise answer without an actual build to look at.