It can be if you're manually dragging the modules. But the other mode is quick and works like you'd want here. Hover the cursor over a module, then hit either "," or "." to move it left or right respectively. Even if you have a pile of little stuff in a row, this can be dealt with in seconds by using those shortcuts.
That's awesome. Those shortcuts should be added to the help page with the other keyboard shortcuts: https://www.modulargrid.net/e/forum/posts/index/2