I put my Arc at the front edge of my table and moved the TV to the rear. It lets me pivot it a fair amount without the TV impacting the Arc.

If your mount can take the additional weight mounting the Arc to it also would work.

I went the way I did as I didn’t want to fool with trying to figure out TruePlay with a movable speaker.

Something like this, which took 5 seconds to find using Google. 
 

Someone used to make a mount for the PLAYBAR that mounted it on the bottom of the TV, I’d be looking for something like that, if it exists. 

Looking at that picture, move the Arc to the front of the cabinet