Strategist Marc Stigter, whose relationship with dumped commissioner Paul Baxter is under scrutiny, earned more than $700,000 by helping to develop a new strategic plan for FRNSW.
FRNSW Acting Commissioner Jeremy Fewtrell told a parliamentary inquiry into the use of consultants on Wednesday he is "far from comfortable" with the amount Dr Stigter was paid.
The relationship between Mr Baxter and Dr Stigter, including allegations the pair are personal friends, has been examined by the Independent Commission against Corruption (ICAC).
Labor Legislative Council member Mark Buttigieg, who sits on the inquiry, echoed concerns from the Fire Brigade Employees Union over a lack of oversight that allowed the perceived overspend.
"You've got this culture that allowed the former commissioner to pretty much employ what looks like a friend on pretty good money to do a 'Mickey Mouse' exercise - 6000 bucks a day," Mr Buttigieg said.
Mr Fewtrell said the service created the new strategic plan, dubbed the Plus Plan, in order to better convey to the public and elements of the government what it does beyond responding to structure fires.
Marketing consultancy firm Brand Council was also paid around $500,000 to help with the plan.
Mr Fewtrell told the inquiry all up around $1.67 million was spent developing the plan in 2017-18, on top of around $757,000 the following year.
"The intention of it was to sort of parallel that understanding that people outside FRNSW didn't have a full appreciation of all the things we do as an organisation," Mr Fewtrell told the inquiry.
Mr Buttigieg asked Mr Fewtrell if FRNSW would have been better off spending the money on new fire trucks and stations rather than a rebranding exercise.
"Within the organisation, there's a much greater level of awareness about these types of issues," Mr Fewtrell replied.
The committee estimated FRNSW has spent around $18 million on consultants since 2010.