Long answer.... Drum brakes are not a "slight drag" system like disc brakes. There is zero tolerance between pads and rotors (some exceptions), however there should be space between shoes and drums. The energy/pressure of the wheel cylinder applied to the shoes is "self enegized" or amplified by the rotating forces of the drum. That is why no power brakes and 4 drums is a drivable system (but barely!) Because of this "self energizing" function... if the shoes are slightly dragging when turned by hand then they are really dragging at highway speed when the drum is turning fast. If you adjust them too loose then drive in reverse 2-5 mph and repeatedly stomp on the brakes... you might hear the self adjuster ratchet the star wheel down, which tightens them to about the right level.... this is how the shoes stay adjusted when they wear down.
short answer... Too tight, adjust them just enough so the wheel still spins freely.
