IMO, it will be 1.)Ingram, 2.)Thornton, 3.)Allen.
But yeah, we definitely will not have a post player who can draw double and triple teams. There's a good chance we won't even have a post player who will average double figure scoring. Which isn't the end of the world, we've seen several championship teams in recent years who did not have much post scoring.
I think Ingram will be able to score all over the floor just won't be a back-to-the-basket player of course. Thornton has the speed, ball handling, and athleticism that we haven't had at the PG spot since Irving. He'll be really tough for teams to keep out of the paint, big question mark, though, will be his jumpshooting. Allen of course can shoot the ball and is an aggressive driver, he'll get a ton of points at the free throw line. I think Ingram has the potential to be a dominant scorer but we'll see, it's also possible that he could struggle to adjust to the physicality of the college game.