As Don said, it varies from product to product.
I've only used wood decks three times. The self adhesive is usually enough, but on one of them I had to go back and squirt superglue in around some of the edges.
I generally am not a big fan...
But for a ship with lots of deck, it can be a plus. Your Snowberry is probably a good one. It's a big model so the deck boards are probably close if not scale, and theres room for adjustment.
Good luck.
One thing you could try is if your deck has any extra, like punch outs for the gun tubs etc., use the piece and test it.