They're not just "bite and claw at human strength." For a start, wolves and dogs can bite much harder than humans can.
For another, the Alphas are regularly described as larger than normal wolves, which means even more strength they can pack on.
And don't discount pack tactics and their ability to move. Overall, their abilities are probably close to the average White Court vampire, and they certainly weren't so useless in Turn Coat.
Plus, Harry is still facing things wolves could be effective against. It's not like every enemy Harry faces is in the god tier weightclass. Fomor servitors, for instance.