the king is probably closer to yamamoto than aizen was in base
aizen would fodder-ize the rest of them without question
but let me ask, where do you put transcendent hollow aizen at? or dangai ichigo for that matter who was superior to him, in comparison to yamamoto, because i think its debatable who would win between dangai ichigo and yama in shikai, he goes bankai and the whole world turns to ash, of course
edit - keep in mind dangai ichigo had a powerlevel that aizen couldnt sense because it was out of his "range" lets say, and aizen in his cocoon form was out of urahara/isshin/yoruichi/s range, then he went ascended out of cocoon form, went butterfly form, then final hollow form, and in that final hollow form he still couldnt feel ichigos reiatsu, then mugetsu ichigo takes it even further than that, how far beneath mugetsu ichigo do you think that final form aizen was in power level? and where would yamamoto fall in line with these 2 if he went all out ?