Ok, i need to clarify something here, i never claimed touhou was larger than anything worldwide. When i said touhou is known worldwide i wasn't referring to sales because i know they would lose without corporate backing. What i meant was Touhou is known worldwide through fanmade material, thats why its more popular than video game sales suggest. Also Touhou fans in general are more likely to be on internet than you would find IRL. Why? Because Touhou has been mainly PC focused. Plus Google Trends doesn't help either since those fans already know where to find what they want. Danbooru have about 614k tags of Touhou pics, the next closest series is Kantai Collection with around 313k pictures. After that is the Fate series 140k
On Pixiv over 2 millions pictures are Touhou alone Fate/Grand Order has a bit less than 300k. Remember this is the internet because of this we don't always know where people are connecting from. Example: I may be in a different country than majority of users here, i don't know that. The next guy that could be from Europe or Asia (Not actually harassing or insulting anyone just making an example here) The point is that people can argue that touhou isn't popular based on sales, however, i can argue back that it is popular worldwide due the amount of doujin material that exist and we don't always know which user is connecting from where. So yes its not popular through game sales, but it is popular worldwide due to the amount fan works that exist. Majority could be Japan but we don't have exact numbers there or the rest of the world. I understand that Danbooru and Pixiv are mainly japanese user based, but that doesn't speak for the whole world, there is the number of people that may not make accounts that browse the sites.
If you guys want to continue discussing this and whether it its valid is all up to you, i cannot do anything about that. Just ask we stop this please no need to prove anything more about Touhou. We have our own preferences and lets all respect that please. (not accusing anyone for bias just stating something natural for us humans)
If we are going to speculate which characters are going to be in smash next, lets do it without being forced to provide proof.