  We study the chaotic properties of a large-spin XXZ chain with onsite
disorder and a small number of excitations above the fully polarized state. We
show that while the classical limit, which is reached for large spins, is
chaotic, enlarging the spin suppresses quantum chaos features. We attribute
this suppression to the occurrence of large and slow clusters of onsite
excitations, and propose a way to facilitate their fragmentation by introducing
additional decay channels. We numerically verify that the introduction of such
relaxation channels restores chaoticity for large spins, so that only three
excitations are required to achieve strong level repulsion and ergodic
eigenstates.
