I'd say he's behind Corey and Nofo. It's a difficult decision because they all have pros and cons, assuming Doueihi is a lock for FB.
Corey is by far the most agile and threatening, but small. His hitups can be fine but also he can get dominated. He's a better low kick fielder but questionable for bombs to the corner, simply because he isn't that large. Corey is a legitimate FB backup option and Nofo and Jennings are not.
Nofo has those Nofo defensive moments but is the better for hitups of the 3. People continue to mock his speed but he showed a clean pair of heels to score his first try and comfortably outpace Maumalo and Hiku.
Jennings is like middle-ground of the above. He runs straighter than Nofo and can make yards, but he always looks like he is jogging. He took a couple of nice inside jinks during the trial, but isn't much for busting tackles and I don't rate him trying to get on the outside of his opposite.
If Jennings had Corey's energy then it would be a no brainer - but he doesn't. I'd go with Corey and Nofo in Rd 1.
Also I have to say, if I recall Nofo doesn't play LHS in his career, I'd love to see Corey outside BJ and what he might do with those offloads. Obv Nofo scored two yesterday and he's a powerful option outside an already powerful centre and inside backrower, but if Corey isn't FB, I don't expect he can do so much about sniffing out the offload from the left wing.