mm it will meet with more stones than the general group,if you want to make both reach a healthy members counting. However,if you promote both,why wouldn't it have a future?
How long have you been into Touhou? As much as i love Touhou,can't deny that as of late there is not that much general burning hype as of ol' times when i joint dA,back on 2010. At least is not that noticeable. With luck that changes with the release of 15.5 orz Tho the fandom comes and goes always.
Anyway,the point is that people tends to go directly to big groups because ya know,more people,more possible views. So,you need to work on making your group have either something special,or just get it big,which will take time anyway. And pay attention to the times when there is new official material,people work more those times.