Da Silva shouldn't be a worry. He's 18 so you'd have to think he's no chance of being ready to carry the load as a starting first grade hooker for another couple of years at least - by which stage Koroisau will be right at the end of his deal. Harry Grant is the best young hooker in the game and his first season in first grade was the one on loan at the Tigers, when he was 22. If all goes well with Da Silva there's a natural succession in place.
Bula seems to have fullback locked down. So we're talking about halves, and specifically the idea that we'd only be able to play two of Luai, Galvin, Sullivan and Fainu. I'm not sure about that, though. All three of Sullivan, Galvin and Fainu are unproven at first grade level and the latter two are also 18, so you'd have to think there's a very good chance at least one of them will either never make the step up or will be injury prone, sign elsewhere after their current contract or any number of other potential pitfalls. Fainu and Galvin are also both 18 so should have reasonable expectations about game time over the next couple of years.
I also suspect Sullivan is somewhat the odd man out. He's on a fairly reasonable contract that would make him not widly overpaid as an X-factor utility off the bench in a good side whereas, on the flip side, he probably has the least up side of all of them.
By the time we get to 2026, when Da Silva, Fainu and Galvin might actually be reasonably thinking about locking down full-time starting jobs I would be pretty shocked to find that we have Bula-Luai-Sullivan-Koroisau as a bolted on starting spine with no question marks at all. And, frankly, if we do I'd suggest we have played finals football at least once and we're probably not too bothered about the 'logjam'.
