That's not 100% accurate.
COAG has elevated any advice given by Australian Health Protection Principal Committee to have equal standing with that given by COAG, which is a major upgrade in the management of the situation by professionals, rather than politicians. The Committee is comprised of the states' and territories' Chief Health Ministers and is chaired by the Commonwealth Chief Medical Officer, who you can assume is the leading decision maker.
The state of emergency declared in Victoria specifically empowers the Secretary of the Department of Health and Human Services, not the parliament or the executive.
Absolutely nail the PM and respective premiers on their messaging and leadership, but understand that they act on the advice given by professionals. Hopefully that's a comfort given the pretty bare cupboard when it comes to associating many politicians and intelligence.