Izumo or Iwami Ginzan?

I am planning my trip to San'in area. I just have 3 days. I'll stay in Tottori so I thought into distributing my days like this.

1st Tottori city
2nd Matsue, is it possible to see the Castle and Adachi garden in one full day coming from Tottori?
3rd Izumo or Iwami Ginzan? I am interested in Izumi shrine but I've been to Ise shrine last year, what would you do in my case? which one would you choose and why?

Thanks

2) yes, it is possible. Matsu is not that big - as also is the garden.

3) i didnt enjoy neither very much (even though i am huge temple and shire fan usually) - but maybe that was only because the weather was very bad.

anyhow i would have here a suggestion to something completly different, which turned out to be my travel highlight of the whole Tottori area: Yushien
https://www.google.at/maps/place/Yushien/@35.4933776,133.171373,17.25z...