Matty is not exactly the polar opposite to Thewlis but he is very different. He is much faster, doesn't have the rugby brain, and has no specialised position. In broken play he is the most dangerous player on the pitch. So the challenge I think is to find a position he is comfortable in and exploit his speed.The FB position is a good one to choose because he can move in and out of the play when he sees a break or is involved in a set move. The disadvantage is that it requires a demanding skill set where he must jump for high balls, organise his defence after adding up the opposition numbers on either side of the ruck, and decide when to move back to cover the in goal area from a kick through.
Thewlis is an out and out FB and the natural stand in / successor to Ratchford. But Ratchford is among the top 3-4 players in our squad so there is no way you would wan't to leave him out of the team. And if you decide to play Ashton, then the only option is to put Thewlis on the wing. He is still only 19 and shouldn't get roughed up too much in that position. And it allows him to use his skills and rugby brain whilst picking up much needed match experience. He is signed until 2024 and only Toby King has a longer contract, so that's as big a statement of intent by the club that you are likely to see.
So regardless of who coaches the team I think we are likely to see this awkward triangle of Thewlis, Ashton and Ratchford and the choice of who fills the FB and wing positions. Price has gone for Ashton at FB but perhaps Powell will swap them around and move him to wing. Either way we don't seem to be in the market for a replacement for Lineham and I can't see a strong contender coming through from the Academy atm.