Okay I think we have been looking this all wrong that tobi can only be someone old who had extensive knowledge of the ninja world and gathered it overtime but isnt it possible that there have been two tobis. First Tobi: Madara uchiha as minato stated he said that only madara has the power to control the nine tails with his eyes and he is aware of nagato so he must have atleast lived a little past when nagato awakened is rinnegan.
Second Tobi: Who knows could be obito,a clone,etc.... There might be evidence but nothing is really solid I personally believe it is obito but yeah I think tobi is the apprentice of madara uchiha the first tobi and then after madara died the apprentice took over his name.
It alaways the body changed busines.. i didint
know ninja feared death that much lol jk. but in
all seriousness thers only 1 tobi left, since
Sasuke killed the original white one as you can
remmeber and the black one has always been missing
literally no one knows ewhere the bastard gets
too. after he leaves. the most we see is the
white. what i have noticed the black one has very
extensive knowldge concerning itmes and history.