ToB classes are the most efficient means. There is really very little difference between a samurai and a knight. Knights have better armor, samurai better weapons. Some Samurai would be very focused on improving their katana skills and kata (sword sage), Some focused on just being the best warrior possible (warblade), and some really followed bushido with their whole heart, and let the kami guide their hand (crusader). For some reason samurai and ninjas have this whole mystique about being soooo different from their european counterparts. A samurai is just a japanese fighter (or paladin, or ranger), and a ninja is just a japanese rogue (higher level ones may take levels in assassin or shadow dancer). The only real diffence for the player is fluff, and even that boils down to religion and culture, and neither rogue nor fighter have any abilities (or even fluff) that tie them to a specific culture.