Try wiring them in series, more power, and they have to stay in sync.
I have my z rails touching the table, as a guide, to keep them rolling straight. I always set my zero and drive it longer past the entire planned cut and then start it. To ensure the whole thing will run smooth, I lost a long job because I started it a bit cockeyed and it stalled out at the far end. I was even doing some measuring last Friday to see how it was doing (testing a cool mod) and it stays really straight, better than I could measure with a tape.
YMMV, but I added some pieces of plywood next to the wheels to force it straight. Mine also has a little travel side to side without these. I called them “hack tracks”, but they have been installed permanently and they work well for me. I didn’t end up installing any on the bottom of the table, but I could do that too. They have an added advantage of keeping most of the sawdust away from the wheels as well.