I run a single 4K monitor setup with a fixed grid of 8 x 8 virtual desktops to work on a lot of projects. Sloppy focus is a requirement: so much natural and efficient. Using alt-tab of upper left corner to switch application is a total vast of time. Either you better have to put widows side by side to not switch at all, or use the taskbar/taskmenu to directly raise the one you want, because on a machine with close to 100 windows the "always changing position in the list" of the atl-tab menu is a nightmare. I use Ctrl-Up/Down/Left/Right to quickly switch between virtual desktop with a single hand. Add Shift to move the focused window across the virtual desktop. There is absolutely nothing floating, moving, growing or shrinking dynamically: no effect at all. This make all the operations immediate, blazing fast, and perfectly predictable in my brain without looking at something other than the task I am working on. In addition, I have found that no effect is the best setup to lowering visual fatigue.
I have tried multiple times to get the same comfort and efficiency with Gnome 3, but it's actually not possible to reach the level of xfce4 or mate. From a high level Gnome 3 look like it can do it, but so many details are broken/unconfigurable that in fine it's just a vast of time.