Are The Dutch Theories Actually True?

After Playing RDR2 and Finishing for the 6th time, I moved on to RDR1 and Also beat the game, However ive been hearing about rumours that "Dutch is a Cannibalist" and "Dutch is Mentally Ill" I just want someone to tell me about it since ive heard about the head injury theory from the train incident in Saint denis and also how his hat is placed, I really dont know about these stuff so experts, ENLIGHTEN ME!