You might be surprised how even people as aggressive or stubborn as this might still find it embarrassing or unreasonable to refuse a lunch-and-learn. Maybe sending a mass invite to a meeting on Python would be seen as passive aggressive, so just start socializing smaller ideas with key people. It sounds like you'd have to be cautious about upsetting people but I think it's always worth it to at least find the most polite and diplomatic ways to suggest things you want at opportune moments. The times I see this backfire is when people let it monopolize their attention or bring negative tone/attitudes.