Thrash Metal There were no real difference between the band sounds, but you've got more bands coming from the East (specialy San Francisco and Los Angeles) than from the West (New York).
From L.A. and San Francisco came bands like Megadeth, Slayer, Metallica, Dark Angel, Death Angel, Forbidden, Testament and Exodus. The West Coast popularly only hosted Anthrax, Overkill and Nuclear Assault.
You got your directions all messed up. West Coast is Megadeth, Slayer, Metallica, Dark Angel, Death Angel, Forbidden, Testament and Exodus. East Coast is Anthrax, Overkill and Nuclear Assault. Then there was thrash from Europe (primary from Germany) called teutonic thrash which included Destruction, Kreator, Sodom and Tankard.
Besides that nice guide. I like how you covered a lot of ground.