Forget about groups, brigades, etc and how many of each go from these.
Per the RCRD all vehicle accidents [whether they are reported as a spill only or as an entrapment] outside of the 'metropolitan area' are to be attended by rescue, fire, saas, sapol. The RCRD specifies which fire and which rescue are to be responded, however it is not setup as a 'first alarm' etc.
CFS SOPs are meant to reflect the RCRD however it is interesting to note that the latest edition of the SOPs [SOP 2.1] lists 'vehicle accident' as a single fire appliance response.