No, centres of trade weren't created by a nation, they could be influenced, but they were generally based on geography. As this system shows. provinces with COT's or access to large rivers have stronger trade power, because thats realistic. Reality provinces weren't jumping trade regions all the time based on stupid things, they were pretty static based on how trade flowed through the world. Growing in wealth and stagnating as different routes were changed.
You talk about how this isnt dynamic? At the start of the game trade flows from the east, through Alexandria, constantinople and other centres of trade in those areas, making the mediteranean incredibly wealthy. Now you as a nation, if you so choose, can colonise strategic positions all along these routes, and divert most of this trade around places like africa, andfeed it up into sevilla, or further on if you can exert that much influence. you've effectively destroyed the mediteraneans trade power and taken it for yourself. Its so much more realistic and dynamic then EU3's COT system, which was dull and way less realistic.