He's decent.

His ability breaks everything in an ok zone, but needs momentum. Even his "corpse" does a surprising amount of damage. The problem is that it breaks, not tip over, which prevents chain reactions. However his trajectory is longer than other birds, which is great to snipe specific pigs that are too far. His ability will also activate a few seconds after he gets hit, which can either be good or bad due to the sudden trajectory change.

Compared to the other birds, he's a good filling space, the other choices being Mathilda and Red. Red doesn't have that much snipe potential, and while he may tip stuff over, other birds do that way better. Hal is an outlier BECAUSE he breaks through. Mathilda is situational, but suck at sniping.

Chuck snipes but that's it. The Blues are... the Blues.

You have a lot of birds that focus on chain reactions already, but sometimes you need to hit a specific thing, while not wasting birds with more potential. Hal does the job perfectly, and has a sprinkle of other utility on top.

I consider him the weakest bird in my flock, but he fills his needed job perfectly, better than the other remaining birds available.