A couple of recent experiences convinced me that, without the right leadership and organization, this is not a good idea.
I was invited to join a newly-formed 'scratch' group comprised of ukes, banjo ukes, guitars, banjo, harmonica, washboard and jaw harp (aka Jew's harp). The leadership was poor at best, as was the selection of songs and printed lead sheets. Folks played in different keys, some weren't playing on the beat, some played from different versions of the lead sheets, and the "leader" would say "good job"

While on a recent trip to the midwest, I played with a (smaller) uke group. Only slightly better leadership, no organization of music/lead sheets, and failure to play to the different skill levels of participants..
Theses experiences made me really appreciate our uke band Music Director. I've known him for many years, and long ago recognized his musical talents (playing various instruments and singing). I came to appreciate his leadership skills while attending concerts of the 85-voice mixed chorus he directs. Since bringing him into the uke band as our Music Director, I've come to appreciate his teaching skills.