Unless you work for Beacon Rail who you know, as the locos owners might have a little more understanding of their locos than a public forum?
Never going to happen.
Exactly as The Planner states, longer dwell times, I believe they won't be able to run at the SP Differentials the 170s work, they're interlinked with other XC Services, they're more costly to operate, they offer lower capacity than a 170 and with the DfT holding the purse strings, it's a total no-go-er. 222's unlikely to head to XC either, and if they did they'd be on the main Cross Country network where such a unit is needed. Not sure why West Mids or TfW would want to give up any of their new units to another operator either. Sorry to be a downer, but the most logical solution here really is the 68s to Chiltern, 175s to someone like Great Western, and XC picks up the rest of the Voyagers post AWC. The DfT may work in ways only really known to themselves (or a select few), but they aren't going to shuffle fleets around the country like a deck of cards on a table.