That's not what it says. It says the conductor ampacity used in determining equipment termination provisions shall be base on T310.15(B)(7)...
310.15(B) says Ampacities for conductors rated 0 to 2000 volts shall be as specified in the Allowable Ampacity Table 310.15(B)(16) through Table 310.15(B)(19), and Ampacity Table 310.15(B)(20) and Table 310.15(B)(21) as modified by 310.15(B)(1) through (B)(7).
110.14(C)(1) tells you that if you have an equipment termination that is rated for (2) #1/0-#3/0 conductors, the termination is rated for 400Amps.
310.15(B)(16) as modified by 310.15(B)(2)(A) tells you that you can use two sets of #2/0 conductors (in separate raceways) in a 65degF ambient to carry a 380A load connected to the termination that is rated for 400A.
David,
I put some thought into your explanation. In this case with 4000A SWBD, I will guess there is copper bus detail for field applied wire connectors to be bolted.
Considering that 110.14(C)(1) is used in determining equipment termination provisions, and although I can't find a definition for equipment termination provisions, it seems to include the factory terminal (copper bus detail) and the field applied wire connector (compression connector of some type because they are using fine stranded wire), the link below shows that it is single sized per conductor.
http://www.tnb.com/pubint/docs/colorkeyed_spec.pdf
Since the 444kcmil fine stranded wire only has dedicated connectors, and we are directed by 110.14(C)(1) to use 310.15(B)(16) for determining equipment termination provisions, it would seem that we are back to where we started. Sizing it based on 400kcmil in the 75 deg column where 6 sets are 2010A.
The only way he can use the "other" ampacity tables, is if he used some type of transition box pair in between which is not practical in this application, AND where the bus detail in the transition box on both ends were "equipment is listed and marked otherwise".