This Crawdaunt set is okay. It has some of the basics covered, like Knock Off, Adaptability and Crabhammer. However, Crawdaunt isn't an effective user of Dragon Dance, because it requires two boosts to reliably outspeed opponents. Crawdaunt lacks the bulk or defensive typing to achieve two boosts.
These problems only worsen if you use Adamant. Without a boosting nature, Crawdaunt only reaches 314 Speed after using DD. Any opponent above base 93 that runs 252+ Speed will outpace +1 Adamant Crawdaunt, which plainly isn't good enough. Aqua Jet is the better solution to Crawdaunt's Speed; 99.95% of high-rating Crawdaunt sets in BSS have Aqua Jet, and very few use Dragon Dance by the looks of things.
You haven't mentioned an item, but Choice Band appears to be the only Crawdaunt set that sees usage in BSS. Its utility looks entirely dependent on the powerful CB + Adaptability Aqua Jet combo, which is absent from your set. Crawdaunt is a strong wallbreaker, but there is no shortage of those in BSS. Realistically, it's an outclassed Pokemon -- especially as the DD sweeper you've turned it into here.
Offensive Pokemon cannot be both slow and frail in lenient metagames like BSS. This is why you've been recommended Pokemon like Greninja and Tyranitar instead.
