  We investigate full counting statistics of quantum heat transfer in a
collective-qubit system, constructed by multi-qubits interacting with two
thermal baths. The nonequilibrium polaron-transformed Redfield approach
embedded with an auxiliary counting field is applied to obtain the steady state
heat current and fluctuations, which enables us to study the impact of the
qubit-bath interaction in a wide regime. The heat current, current noise and
skewness are all found to clearly unify the limiting results in the weak and
strong couplings, respectively. Moreover, the superradiant heat transfer is
clarified as a system-size-dependent effect, and large number of qubits
dramatically suppresses the nonequilibrium superradiant signature.
