The post sleeves for my Azek railing fit loosely on the 4x4 posts. This may be obvious, but do I rely on the railing bracket screws to tighten the sleeves against the wood posts?

I'm assuming that the first section of railing would jam the corresponding sleeves outward against the posts, and the following one would attach to the sides with a small gap between post and sleeve. Of course, the screws are long enough (2 inches) to bridge any small gap and still have plenty of wood to bite into. Is this correct? Thanks.