With the way the competition is run, they'd be a realistic chance of squeezing a Top 8 spot by 2019 provided they're on point with their signings. Let's not pretend that making the Top 8 is some great achievement either, it really isn't, especially in a competition that punishes you for success and long term planning.
I don't think they'll miss either Gagai & Ross. True they have been two of the Knights better players, but they're not irreplaceable and given Gagai signed on when the Knights were absolutely desperate they probably weren't getting value for money.
As for the Saifitis, I can't think of many forwards in their age group making the type of impact they're making. Who else is there? Asofa-Solomona & Pangai Jr? Daniel is ahead of them as well as a bunch of '94-'95 prospects as well. Granted front row forward development is difficult to get a handle on, and a 195cm 125kg prop is going to make an impact regardless of age, but I wouldn't turn my nose up on him.