I've been trying it with the F-86 in FS2004 lately. I've been messing around with formation flying off and on for over a year but I still can' really keep my position very well. I was curious though, would it be easier on the wingman if the lead to tried to maintain a certain airspeed, or just maintain a certain power setting. When I think about it I can't see how speed would help because it would be changing so constantly during maneuvers, but whenever I accelerate for a loop I always end falling way behind the "lead" plane.
Any help appreciated. I hope that question made sense too.

The short answer is that the wingmen are always going to be making throttle adjustments to maintain formation position, regardless of whether lead is flying a constant power setting or airspeed.

Any power setting change lead makes needs to be called over comms to the wingies so they can adjust appropriately. In effect, good comms procedures, good situational awareness, hands on the throttle at all times making constant adjustments to stay with lead is what it takes to be able to hang on the wing or in slot.

I hope that helps. I'm sure some of the other team members can give a much more in-depth answer to your question.