Fighter Payloads

I have always wondered about why certain fighter and attack aircraft (as well as bombers) are limited to a certain payload. I am mainly confused when it comes to the F-16. Most sources I have seen state that max payload for the F-16 is about 20,450 lb. The Mitsubishi F-2 has a max payload of like 19,840 lb. This doesn’t make any since because the F-2 is a slightly larger aircraft with a much larger wing and additional hardpoints. How is it the F-16 can carry more. Other aircraft such as the F-4 (18,700 lb.), F/A-18 (17,000 lb.), and Eurofighter (14,300 lb.) have smaller payloads than the F-16, yet they are larger and more powerful. Is this 20,450 lb. for the F-16 a false figure. I have seen much lower for the Falcon indeed, but most sources seem to stick to that 20,450 lb. mark. This makes no sense to me. I mean the F-15E has a max payload of 24,500 lb. This is not much higher than the F-16’s supposed payload and these two planes are a world apart in terms of size and weight. Then you have an aircraft such as the Super Etendard, which most sources say about 4,630 lb. I have seen 9,920 lb. a few time and that is the figure I go with because of the fact that the SEM is the size of an A-4, AMX or other such light striker, and 4,630 lb. just seems entirely too low. Could this be the maximum load under carrier launch conditions, with 9,920 lb. being maximum from land bases? Some help no these questions would be nice.