I think I can now follow the tinycore boot sequence:
init -> inittab -> init.d/rcS -> tc-config -> init -> /root/.profile -> /home/tc/.profile -> /usr/bin/startx -> ( xsetup.sh) -> /home/tc/.xsession -> Xvesa, jwm & wbar
It looks like microcore follows the same boot sequence as tc and everything downstream of tc-config execution is the same as tinycore. Is this basically correct? Of course there are tests along the way to avoid starting up the X environment based on a variety of "status states".