Mando is more skilled and experienced, but Mugmans physically better with arguably better flight. Mugman has better variety, But Mando has better aim.
Honestly. I think Mugmans to tough and varied here. Mugman has better flight through better height, multiple weapons, and more controlled flight. His dash to avoid attacks would work some wonders, and considering he has experience dodging Danmaku, someone who fights without it is going to have an extremely hard time Landing hits. Mando May have some skill to Pull off getting shots in. By Mugmans varied attacks, better flight, dash to avoid attacks, experience dodging a lot more attacks at once, and most importantly, Physical advantages. Mugman probably takes It