DharmaDefender, very logical point you made above. Thank you. It is this logical link of cause and effect that makes Buddhadharma so attractive to people of today.
Related to the importance of the Tulku system, there is also logic for such a system to exist and continue. Highly attained Masters have dedicated lifetime after lifetime to Dharma work. As they take the form of mortals in our realm, they must leave. Therefore, to prevent their work from loosing pace whereby they need to start all over again at every rebirth, the Tulku system allows them to take off quickly and smoothly from where they left off with the same discliples and “tools”.
Looking at it this way, it is us (sentient beings trapped in samsara) who need the Tulku system more than the Tulkus themselves. Therefore, it would be beneficial not to question this system that has existed and benefited us with endless results for so many centuries.