Beat me to it! Works with bombers and fighters. As explained to me, even with REAL flight...the Wingman had to have more throttle to be available to maintain formation. So lead flys a bit lower throttle setting. It helps the group hold position better even in more turning 
It was easy to figure that it would be an issue if flying at max power when HTC first introduced it. I found that flying at E6B's cruise setting was the most ideal (for me) when leading a formation of bombers. The only time they would need to be aware is during bomb run. Unless going "full historical"*, when the others jumped into the bombardier's seat to "aim" it would "break" wingman. So they would need to make sure they got "settled" into cruise setting during bomb drop as to maintain somewhat of a formation during drop. It also made it easier to reform after since lead would be at cruise the entire time, allowing the others to throttle up and quickly get back into position.
*Note: By "full historical", lead would do all the lining up and aiming. Others would drop when he dropped without any lining up and aiming on their part. Really only viable against a town or strat though. Would be almost completely ineffective against a base unless you were dropping on it just to drop on it.
