If you need to type numbers really fast, of course there’s no beating numlock. 10 key for the win. Of course that doesn’t get at why not just leave it as 10 key forever and skip the arrows. I know a lot of older programs… like msdos older…required the use of the arrow keys. And some people do prefer it for their cursor, and it doesn’t hurt to provide the option.
I don’t see machicolations, so I’m not sure how you can call this a legit castle.