Here, something you may have missed is the difference between ,(our good old comma) and 、(顿号), called an enumeration comma and is typical to Chinese. Because of it, there is no possibility to misunderstand that the "2 doctors" could somehow be the paramedic + a nurse suddenly grouped as "doctors", it's a list of people. So, your understanding is correct, that's 4 people.
If you have ever been to China and had to deal with the police, this shouldn't really come as a surprise... ;)