Multiple Righteous Fire Totems Stacking

raics is correct. Perhaps the quoted text would be a little clearer if it used "kind" instead of "source", but that can also be misinterpreted, particularly in the "different kinds of burning" cases.

Stacking rules for buffs/debuffs/etc are defined in terms of that specific buff/debuff/effect interacting with other applications of that same effect, not with other ones that are similar (Curses are a specific exception to this).