Yes, if you have more time to play, you are generally a much greater asset to your faction. If someone could do what you do in 16 hours in 2 hours and net the same results, it better be because they are way better than you and not because they don't have much time to play.
I cant think of a system thats actually rewarding and fair that would penalize someone who puts more time into the game than another person by virtue of equity. So yes, power gamers imo should be rewarded with greater rewards than casuals because they are by definition, better at the game than those people since time in game is a signifcant factor in determining how strong/efficient someone is.
What is needed is a reward system that is satisfying enough to draw participation out of everyone on some level. But also incentivize people with time to do extraordinary things for their faction.