So I played a coupe of tens of hours of the demo during the weekend. The best experience during that time was one run of that stronghold on hard where I was playing premade with my friend. We had one extra player at the start but they left not far into the mission. We ended up playing the rest of the stronghold duo. It was so fun not having to wait for teammates who move more slowly or steal mission objectives and don't realize they should bring them back. My friend being a competent player combat felt as easy as with a full random party. I also had one run where I played halfway solo on my colossus before infinite loading. That was pretty fun too.
My point is please allow us to play strongholds in private! Don't take away that option that we have in most similar games. I do believe that will make this game better for me. For me and many others who want to play stronghold in a less casual way.