I think someone above made a good point.... rather than making it competitive perhaps the skins should be tied to final tier reached.
and then on top of that - to give a bit of incentive to play it could be to qualify for each "thing" a minimum but importantly pre defined contribution needs to be made.
So for instance in this CG,
if tier 1 is reached the reward could have been gunship PJ but and a minimum personal contribution of 5000 tons.
if tier 2 is reached the reward could have been the corvette PJ but with a minimum personal contribution of 15000 tons.
if tier 3 is reached the rewards could have been 200 arx (or if that is too generous maybe bonus 50mil credits, or perhaps some hard to get mats) but with a minimum personal contribution of 25000 tons.
so this would be completely cooperative, but at the same time you still have to put the legwork in to get it done.
That's a good addition. I had in mind forum posts being like "come on, make it to tier 2/3/4! I really want that skin!".