Trindall has started the year fairly well. I would expect him to take on more and more as the year progresses, you don't overwhelm a young half with too much responsibility at the start of the year in a winning team.
I think the potential benefits in the longer term are. An arial threat with his height, work out of yardage with his size and speed. Like I said though, I do like Sione, but I just see Stonestreet being the better long term option. Could be wrong.
I think Jack starting over cam provides some more size and strength in the middle to start the game on the front foot. I would start Williams personally. I probably would start him now as well.
So for me the smart thing to do would be to give them both minutes throughout the year and rotate them on and off the bench a bit. As soon as there is a bit of a niggle with one, play the other. Play for a couple of weeks and then swap, keep them both fresh and hungry.
Given we have four forwards on the bench I am sure we would manage if we picked a different style player. Not to mention Talakai could move to the middle if needed.