Mismatching brake linings can easily make drums brakes grab. Look at the edge of the brake lining, and see what designation the front and rear shoes have, FE, and FF are common designations. It tells what composition the lining is. Ideally you would like the front and the rear to match on a 4 wheel drum brake system.
Just to show you how much it matters, I used to drive 18 wheelers, the mechanics for some reason only replaced one half of a set of brakes on the steer axle. When braking it would literally rip the wheel out of your hands. They tried all kinds of adjustments, and parts swapping to cure the problem. Finally someone looked at the brake linings side to side, and determined that they didn't match. Replace the linings with new ones, and no pull at all. They screwed around with it nearly a week before they found the problem.
You say the problem showed up after changing brake shoes, so it's not far fetched to have a mismatch, all brake linings are not created equal, and it's not hard to check.
My preference is new linings, and new shoes that are riveted, not relined shoes, and not bonded linings. For over 50 years twisting wrenches my findings are that cheap linings, and relined bonded shoes will give you inferior brake jobs.
