So yeah. Seamus is willing to help with this but since he's not a leader he's gladly taking the back seat in terms of ideas and effort. As long as the theme is middlingly neutral and not like, a Muggle slaughterhouse or something, he's just doing what he's asked.
He is not that great and arts and crafts, he's middling at Charms. His best subjects are Muggle Studies (old version) and Runes.