In the past, every time I've installed Xfce on any distro I've had to run through the ritual of installing Compton(display compositor) and/or running a set of config entries that seem to be almost as old as Xfce itself. It didn't seem to matter if the card was Nvidia, Radeon or Intel, config entries of some type were needed to prevent tearing. After installing MXLinux19 I noticed it came with Xfce 4.14, an update over 4 years in the making. There are a lot of nice little improvements in 4.14 but probably the largest I didn't notice at all until a couple of days later(or 10 minutes ago). Usually after I do a reinstall and run a browser or watch a video of any kind the tearing is bad enough to have me drop everything and spend the next 15 minutes messing with Compton and scrabbling to find where I pasted the last working config. It's that bad, or at least it used to be.
It seems like Xfce now supports vsync out of the box and it just works. The little mouse is roaring or at least emitting a loud squeak.
So he did, I've not had tearing issues with XFCE in Arch Linux or Manjaro.