Is a 3 hour tour enough time in both Cortona and Orvieto? Don’t have a lot of time. Should we concentrate on only one city for a full day or day and one-hall??
Three hours isn't even long enough for Orvieto, which has a lot of of actual sights for a place of its size in addition to the charming historic center. Whether Cortona has enough to keep you interested for three hours I don't know, but other folks here will.
I'm slow so I would just visit one of the two. But it depends on how you travel. Plenty to see in Cortona. Here's what we did on a day trip
https://slowtravelitalyspain.blogspot.com/2020/11/tuscany-september-2020-cortona.html?m=1
Both are great cities but I have to agree that 3 hours would not work for me to visit both.