K, I had a AC double disc plow with my D14, it worked great,
I am thinking the cross chains you speak of are just check chains to keep the plow from going to far left or right,
have nothing to do with the plow tracking.
the rear disc guide blade is the key to proper tracking operation of a disc plow, it must be in "good to excellent" condition and properly aligned to keep the plow going straight, If properly aligned in hard ground, it should work in the softer ground, I never remember having that type issue, as my rear disc blade was in good shape and aligned properly
I have attached two pictures of AC disc plows I found on internet plus my Ferguson disc plow,
note one AC plow, the rear disc guide blade is worn down to an unserviceable condition.
another the rear disc guide blade is much larger, therefore it will dig deeper into the furrow and keep the plow going straight.
many old disc plows were placed in the fence row when the rear disc blade worn down as they would no longer track.
my friend and I have two Ferguson disc plows, both had to have the rear guide blades replaced when we got the plows.
get all your guide wheel adjustments bolts free, so you can make some adjustments.
you may have to replace the guide disc blade to ever make the plow work properly,
or at lease be able to adjust the angle it bites into the furrow, but it has to go into the furrow deep enough to hold back the pressure of the plow pushing against it. if worn down it can never do this to your satisfaction.