In general, when moving to a narrower tire on the same car, the surface area touching the ground (contact patch) will still be the same, except that the contact patch on the narrower tire will be longer and narrower than the patch on the wider tire. A longer, narrower contact patch is good for things like snow traction, fuel economy etc., but in general, not as good for handling, dry traction etc.

So a 225 is certainly doable, but will likely handle worse and look a little stretched on a 9" rim. There is a website where you can search for pics of different tire size/rim combinations:
https://tyrestretch.com/9.0-225-30-R20/9.0-225-30-R20/