Playing Roosters, Storm, Sharks and Broncos (and Panthers to some extent) we will know that if they make the top 4 they have earned it, and they will have beaten some handy teams without Thurston to get there.
So if they can win before the finals without JT, they can win in the finals without JT.
So if they can win before the finals without JT, they can win in the finals without JT.