I understand your thoughts on that rear bushing of the A arm.

Mine seemed tight too.

The play or noise comes from the stud in the bushing being able to to move front to back as well as round and round in the bushing sleeve.

It's not much. Maybe a quarter turn on the nut.

Where I screwed up was when I was doing my struts.
The arm held its self up so tight that I could not get the arm to drop far enough to get the strut out. Like an inch was all I needed to clear the spring out of the tower so I loosened both ends.
I did not have to do that on the right side of the car.

From that moment on clunk. I had to retighten it twice.

Hence, I removed it to find out how loose the nut got as it came off completely.

That nut looks like it was hit by a Photon Ray from a Starship with all the craters I put in it now! (-:)

Your nut under there does not appear all that loose.

From the way mine spun off, I think the stud is a little undersized from the factory. It might explain why the arm was so tight.
I would have changed the impinged nut, if I had one at the time, just to see which was worn or made wrong.
But I finally got the clunk stopped or you might say, fixed. (-:)

I advise you to consider the cheat to double the length of your wrenches. Either by pipe or by hooking another one end to end to get that bugger tight enough.

It's a tight place it there and my socket fitting collage of tools won't fit in there.

Good luck.
I hope working up in there takes that clunk away for ya!

Phil