Why don't you just look it up instead of actively arguing an assumption?
This reactor type has 73 assemblies of 5 rods each.
Nuclear safety regulations require that the control rod system must be powerful enough to bring the reactor completely subcritical with all Control Element Assemblies (CEAs) inserted minus one assembly stuck in the fully withdrawn position.
One assembly (or 3) inserted would not bring the reactor subcritical.
Yup, this is me focusing on US Navy reactors, which is my experience. For them, a rod would already take you sub critical.