What you say is partially true, but it also is not exactly correct. You only need the Class A license if the total combination GVW is over 26,000 AND the trailer being towed is over 10,000 lbs. So an 11K pickup towing a 14K trailer does not need a Class A in NC. Same for a 25K truck towing a 9K trailer does not require a Class A or Class B. Almost all states are like this, although there may be a few exceptions (CA??).
So, you can see there is an advantage to a 9,900 lb titled trailer in that you can tow it with a 26K truck and no special license. It can also help to keep your combination weight under 26K when towing with trucks rated up to 16K GVW.
From the NC Driver's Handbook, Pages 11 and 12:
Regular Licenses
Class A Required to operate any
combination of vehicles exempt from CDL
requirements with a gross vehicle weight
rating (GVWR) of 26,001 pounds or more,
provided the GVWR of the vehicle(s) being
towed is greater than 10,000 pounds.
Class B Required to operate any single
vehicle with a GVWR of 26,001 pounds or
more that is exempt from CDL requirements, or
any such vehicle while towing another vehicle
with a GVWR of 10,000 pounds or less.
Class C Required to operate any single
vehicle that is not carrying hazardous material
in quantities required to be placarded or is
designed to carry no more than 15 passengers
including the driver with a GVWR of less than 26,001 pounds; or any vehicle towing a vehicle which has a combined GVWR of less
than 26,001 pounds operated by a driver at
least eighteen years old. Most drivers need
only a Regular Class C license to operate
personal automobiles and small trucks.