s61n, I'm totally bemused by your interpretation of a very straightforward paragraph. The 19 seat figure is also used when considering the carriage of cabin attendents, so perhaps that might help with your interpretation - more than 19 seats requires the carriage of a c/a, 19 or fewer does not (or as JAR says "19 or less" but that's a different story....
) Same logic. That's why large helicopters generally have a MAPSC of 19 in the civil role
PS. Regardless of my take on it, if JimL says anything about OPS-3 you can be pretty safe in believing he's correct
