  We show that incompatible ``higher-order quantum theoretic testing
procedures", known as quantum testers, perform better in distinguishing causal
quantum networks than its compatible counterparts. To demonstrate our finding,
we consider a specific two-party quantum comb discrimination (QCD) game based
on the task in which a receiver gets a black-box that implements a quantum comb
and they attempt to determine which comb it implements based on prior
information. We show that the receiver does better at winning the game when
they have exclusive access to incompatible testers over compatible ones. Our
investigation generalises the earlier finding that the incompatibility of POVMs
is a {\em bona fide} resource in quantum state distinguishability. We also show
that any quantum resource in testers is useful in comb exclusion tasks using
the resource measure, {\em convex weight}.
