Health Secretary Alex Neil unveiled the scheme to site the bases in Glasgow, Edinburgh, Aberdeen and Dundee, to "deliver the very best possible outcomes" for patients.
But the group of surgeons, emergency medicine consultants and paramedics who put the original proposal to ministers had concluded "the population size and incidence of major trauma in Scotland indicate the need for one, or at the most two, major trauma centres (MTCs)".
The centres will treat around 1,200 patients a year who have suffered major traumas, including serious head injuries, burns and knife wounds. It is hoped they could save up to 40 lives every year.
The bases will be operational from 2016 at Edinburgh Royal Infirmary, Ninewells Hospital in Dundee, Aberdeen Royal Infirmary and the new Southern General Hospital in Glasgow.
Ian Ritchie, president of the Royal College of Surgeons of Edinburgh (RCSEd) and one of the authors of the original report, said: "Having four trauma centres for a population of five million gives me concern because there might not be sufficient volume of major trauma cases to justify the expense and resource and produce the team working and the good systems and the good outcomes that have been shown to be delivered by trauma centres elsewhere."
A number of trauma centres have already been established in England.
The idea of MTCs for the most seriously injured patients originated in the United States. In the 1980s an early study in Orange County, California, found a 19% reduction in the rate of preventable deaths.
The Scottish report, published by the RCSEd, said: "It is recognised that there is a volume-outcome relationship in major trauma care and it is recommended that an MTC should see at least 400 major trauma patients each year.
"MTCs with a sufficient volume of work to gain experience in managing these patients have demonstrated a 15-20% improvement in mortality.
"Conversely, low-volume MTCs have little impact on patient outcomes. Each MTC should serve, therefore, a minimum population of approximately two to three million people."
It is estimated that there are around 1000 major trauma incidents in Scotland a year.
The college report made it clear patients more than 45 minutes away from an MTC should be given immediate treatment before being transferred.
In a statement that will be put on the RCSEd website, Mr Ritchie said he appreciated there were political sensitivities around the shake-up and the imperative was to create MTCs. He also said the Scottish Government's four-centre plan would improve patient care.
Mr Ritchie said: "I really hope all of these [four] trauma centres will be keeping evidence and good data on the patients they manage so we can see over time whether we do need two."
The RCSEd report, which involved a range of clinicians from different parts of the country, also focused on the need to improve rehabilitation, describing current facilities as insufficient.
A Scottish Government spokesperson said: "The consensus of the expert group behind this work, which included representation from the Royal College of Surgeons Edinburgh, is that four sites should be enhanced to provide definitive major trauma care.
"We recognise there are conflicting views on the number of major trauma centres required, and this is why we will be enhancing existing services gradually.
"It will be important that the four centres operate as hubs within a national network to improve care across the country, not just at the dedicated centres."