The difference here is that the sheer rate by which Harris is increasing the churn of players through use of the waiver system versus Avila increases the chances of finding useful players, and who knows, maybe even an undiscovered gem. Even if the hit rate of getting a WAR-positive player onto the roster is one in 10, it's worth the effort, because as an example, one in 10 out of 100 is worth far more than one in 10 out of 10.
Christian Walker, Ramon Urias, and Jorge Mateo were all 3+ WAR players picked up by their current team off the waiver wire. The latter two by the Orioles, a team very much in our boat the past few seasons, and an organization we could do worse than to emulate when it comes to player acquisition.