So players who are willing/able to spend more money on more alt accounts are able to have an advantage over ones who are are not willing or able to spend more money on alt accounts?
Not sure I will ever agree with the idea that someone who is able to use a recruit a friend program to start up multiple accounts should be able to gain xp faster then someone who isn't able to.
Maybe an EXP bonus to use LFG for missions; perhaps bonus applies if grouped with characters you have not grouped with in the last X days or something or not within your guild, or both.