Twal should hopefully turn into a solid first grader. I'm not expecting rep-upside but I think a fair projection will be a valuable contributor to first-grade. Aaron Woods is a reasonable comparison. Big motor, high quantity, solid quality type prop. Twal has some ball skills before the line - like any good, modern prop. He has added a nice bit of size over the pre-season but I wouldn't be surprised if it took him another year or so to find his ideal playing shape in 2018.
Morris is an interesting one. We are currently very deep in the backrow so odds are he just plugs away in the ISP this year. He was very good in the NYC last year. Not in a flashy way nor through stat-padding but consistently there would be plays where you sit-up and go 'who did that?' and invariably it would prove to be Morris. Someone forced an error due to a big hit? That was Morris. There was a massive cover-tackle made to prevent a break? Morris again. We scored an improbably try due to a big kick-chase? Yep, Morris.
Luck may be an element to it but he was consistently putting himself in the right position to make these splash plays through out the year. 100% effort player in that sense. Never stopped playing and as such he made plays.
As for who he comps well to in the NRL...I don't think Josh Jackson is an unreasonable play-style comparison. Busy backrower that makes an impact on both sides of the ball while lacking some of the prototypical size of a modern edge forward. Physical profile wise (185/186cm, ~103kg) I think he is actually a great match to Beau Scott and I believe he has spent a fair chunk of time working with our enforcer in the pre-season.
Morris was the only depth player to pick up a multi-year extension if I recall correctly (which stood out to me at the time because we have made heavy use of 1-year deals for depth players under BA), so there seems to be some hope that he will progress forwards in 2018 if not this year.