This is already possible with 'hey'. For example:
hey Tracker set Frame of Window 2 to "BRect(1329.0, 65.0, 1905.0, 968.0)"
Be careful, Window 0 is the Desktop and Window 1 the Tracker status. you can check what's what with:
hey Tracker get Title of Window 0
Stack&Tile is not finished, just good enough for R1.
Many things are possible and have been thought about over the years. From possible auto-tiling and -stacking to better visualisation of the fact windows are tiled/stacked etc. The first step is solving ticket #7868 "Create public API".
That should make all sorts of things possible for applications.