If you have several windows open, for example 25, and when you press ALT+TAB the window you want to go is in the 13th place (see picture) then you'll have to press TAB 12 more times before releasing ALT in order to select and switch to that window.
It would be much faster if you could use your arrow keys, because you would only have to press DOWN ARROW twice and RIGHT ARROW once (or vice versa) - JUST THREE KEY PRESSES - to get to that window thumbnail/icon.
And three key presses is much faster than TWELVE key presses.
Of course this is not as likely if you have just a couple of windows/programs open. But if you have three or more, It'll be ALWAYS faster to use the arrow keys than to press TAB several times.
All ideas are welcome (remember I'm just a beginner who wants things to be easy) EXCEPT TELLING ME TO USE ANOTHER WINDOW MANAGER! I'm looking for the solution in Mate, not in Gnome or any other desktop.