yah, actually in my ngondro text right in the beginning it is said that Lord Jigten Sumgon said that before the ngondro you do the four foundations that are the foundation for practice. and after that he says the foundational practices ( ngondro ) are even more important than the higher practices that you should definitely do before engaging in higher practices. and tummo is a completion stage practice so no hurry. as a layman if you only practice tummo enlightenment seems quite far away. better to follow the complete path as taught by past masters.
If the thought of demons
Never rises in your mind,
You need not fear the demon hosts around you.
It is most important to tame your mind within....
In so far as the Ultimate, or the true nature of being is concerned,
there are neither buddhas or demons.
He who frees himself from fear and hope, evil and virtue,
will realize the insubstantial and groundless nature of confusion.
Samsara will then appear as the mahamudra itself….