Although now that I read my post again, it wouldn't address your issue since some missions would still be pretty much out of reach for either group of players...
But I could see system security play a role here in affecting the difficulty of missions, so that wings interested in wing content (or solo players interested in more challenging content) would know where to go in general.
I wouldn't mind that if the volume were enough, let's face it, there could be a numbers hike across the board. I know pretty much how many missions a faction will have now by looking at the faction details in the right panel. The only time you get 20+ missions is when 15 of them are the same type, caused by states.
But yeh, I was surprised by this implementation of wing missions. Surely it would have been better to come up with code that simply splits any prize from any mission completed by multiple members between them equally and balance the payouts based on that and the difficulty of the mission? Meh...