Hello there,
I have a ranger that I took one point of scoundrel with just so I would have 2 charms. So far I can charm 1 with an arrow/scoundrel touch but regardless what I try for the second the spell always fails. I am not sure if it is just bad RNG, bugged, or simply cant be done. Before the last patch me and my co-op buddy reloaded a mid battle save and tried 4 or 5 times in a row to charm two baddies at the same time and the second attempt failed every time.