You can use JXA in the Script Editor or Automator to set the location of a window to an exact location and size. It is easy to set up the one-line script and reuse it by simply changing the application name and size numbers. You can also create an Automator service to repeat a setting you use often.
The latest version of Numbers restores our ability to use AppleScript to automate some actions in your spreadsheets. You can use AppleScript to create new commands in Numbers and do things that could be difficult or impossible to do otherwise. Take a look at some simple examples that populate cells with random numbers and modify the values of checkboxes.