Castle Siege and Coliseum stage origins?

For the fire emblem fans who also play smash bros, was it ever agreed upon what games these stages are based on? you see in smash bros ultimate they are simply said to be from "fire emblem" the series, not a specific game. if they are simply supposed to be generic medieval like areas that are based on fire emblem then fine, but id like to know which game they represent the most. ive only ever played three houses and engage(newgen i know) so i dont know.