As you say, Mike Maguire offers a three-part typology of burglars. His typology differentiates burglars based largely on age, dedication to criminal activities, and methods of committing burglaries. His three types are low level, middle level, and high level burglars.
The low level burglars tend to be the youngest group of burglars. These are people who do not put much thought at all into their crimes. They tend to be very opportunistic. They simply see an opportunity to commit a crime and they do so immediately. They do not plan their crimes at all. There is no time lapse between the decision to commit a crime and the act itself.
Middle range burglars tend to be older than low level burglars. They are also likely to put more thought into their crimes. They might plan to commit a burglary but not do so immediately. These are people who are not necessarily professional burglars, though. They typically have legitimate jobs but will occasionally commit crimes. Although they are not professionals, they are likely to be more skilled than lower level burglars and more thorough when they are burgling a home.
The high level burglars are the most professional and the most skilled. These burglars are much more likely to do a great deal of planning before their crimes. They might plan to commit a burglary, select a target, and then do more planning before they actual burgle the house. They are likely to make their living from burglary and are willing to commit crimes over a wide geographic area.