OK, classroom time from the old teacher!
Will someone tell me what, if any effect shoe adjustment has on hydraulic brakes? A properly-operating hydraulic brake system cannot pull to one side or the other due to adjustment problems alone. There will be NO braking until all the shoes are in contact with the drums, allowing pressure to build up, so adjustment problems can only cause a low pedal, not a pull.
However- - - - -if there is any type of restriction, especially in the front brakes, the vehicle will pull toward the good brake. Let's say, for instance, there's a collapsed flex line to the right brake. This delays application of that brake, and allows pressure to build in the other wheel cylinders, and the vehicle pulls toward the brake that IS applying, the left side. A sticky wheel cylinder will do the same thing. I'd start looking for a bad flex line, or a sticking wheel cylinder, not an adjustment problem.
Jerry
