Mr O'Farrell has downplayed speculation he is out to lower Mr Baird's prominence in the cabinet by listing him at number 11 on the new government's line-up of 22 ministers.
A document placed on the government's website on Monday showed the authority for land tax, gaming tax, payroll tax, public service superannuation and the Office of State Revenue had been transferred to finance minister Greg Pearce, News Ltd reports.
"It's not true that this is the first time in history that this has happened," Mr O'Farrell told Macquarie Radio.
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"We had a minister for revenue once. I'm not sure that some people understand that."
He also noted that Mr Baird was listed in 11th position as treasury spokesman when the coalition was in opposition and that the former Victorian Labor government of John Brumby had done the same with its treasurer.
"The batting order if you like, the seniority levels, have not changed since last term," Mr O'Farrell said.
The coalition government would not resort to political infighting of the kind which led to Labor's downfall in NSW, he said.
"At some stage the media will wake up that we're focused on the public," Mr O'Farrell said.
"But the old story they used to be able to write, which was certainly true under the former government, simply isn't an issue for the new government."
Mr Pearce dismissed Mr Baird's position on the ministry list as arbitrary.
"Lists are lists and you can use them for whatever purpose you want to," he told ABC radio.
"It's just a listing of our team."
It is understood that Mr Pearce was Mr O'Farrell's first choice as treasury spokesman when the coalition was in opposition, before pressure from the moderates faction forced Mr Baird's promotion to the job two years ago.
Mr Baird has often been viewed as one of the top coalition contenders for premier if Mr O'Farrell were to vacate the position.
