I would agree Alex, but I'd still say that Azumarril is the overall better Pokemon (or at least, overall more useful to a greater number of teams) just because survivability is so important (bulk or Speed). What I really hate about a Wall Breaker with no survivability is that it almost has to come in on a revenge kill (meaning you already lost something), will only kill one enemy (since it's not a set up sweeper), and because it's a wall breaker and not a trapper, it can't even selectively "choose" what to kill (the enemy decides what to sac).
Obviously, a good wall break can make or break a game, but Azum can still successfully wall break, while being a major defensive asset thanks to its much more impressive bulk (the ability to take Special attacks is huge too, seeing as Crawdaunt can't even really take resisted ones) and much better defensive Typing. This means that Azum has more chances to Wall break, and supports its team better (important for a wall breaker, as it's not usually a win condition-- though obviously Aqua Jet gives both a chance to do even that).
I guess my point is I'd choose Azum over Crawdaunt for a 7 times out of 10-- but that's just because most teams will have a greater need for all the defensive backup they can get, and need those extra resistances to count on. However, there are those 3 teams that I'd go with Crawdaunt for because of what it can do that Azum can't (hit harder, and royally fuck shit up with Knock Off, which eliminates a lot of need for prediction since everything hates losing its item).
Ultimately, I'm not even sure if it's all that necessary to compare them directly.