A bomber is classified by its bomb load. The list being:
Light Bomber - 2,000 lbs
Medium Bomber - 4,000 lbs
Heavy Bomber - 6,000 lbs
So there you have it. Is that what you were trying to say? I could barely understand it.
As larry said,
Seeing that the Ju-88 is a medium bomber you are wrong.
You ARE wrong, as another example is the A-20 or the G4M1. The A-20 is classified as a light bomber, and it could, and does in game, carry 4,000lbs of ordnance. The G4M1 carried 1000 kilograms, or slightly under 2,205 lbs, yet it is classified as a medium bomber.
AFAIK a bomber is classified by its weight, not by how much it carries. Its classification is also determined by the country that operates/operated the craft. An example would be the Ar 234, which was classified as a "Fast Bomber" by its country of operation, Germany, not a "Heavy Bomber" like your list would suggest.
Little tip: Before you make blanket statements, spend time researching for an exception, as there always is one.