IMHO, there is no way to judge a tank's bio load from what kind of fishes/livestock u keep. the biological filtration of an old but proper setup can naturally handle a higher bio load then a new but immatured setup. other factors include skimmer capabilities, size of tank, usage of NNR, etc......
juz for illustration,
some reefers can keep a school of tangs/anthias in a well setup matured tank and be successful, but some can even barely keep a anthias/tang in a newly setup tank.