As far as appearance goes, I know some very experienced aikidoists who fall on the rail thin side of the spectrum as well as short and portly. From my experience with them on the mat, I can guarantee you that their appearances bely their abilities! I would be careful about falling into the trap of what an ideal physical appearance should be for a martial artist. In fact, I know a particular sempai who told me that the reason he started aikido was after watching a "short fat guy toss people around on the mat like ragdolls at a demo."
Second, I also think you have to be very careful on how you define "warrior." As far as I know, that definition can change across almost every culture on the planet. And I don't quite follow your definition of "classes." I disagree that there even exists a warrior class in our society today, at least in terms of modern sociological theory.