Let the Scions stay in Eorzea while we go off on some new adventure to Meracydia or the New World or wherever. Give them a sendoff where they tell us we can always call on their help in times of need or something (justifying being able to call on them for Trusts, without needing to have them front and center all the time in the MSQ), maybe use them for cameos or side stories once in a while, but take a break from them for a bit.