2 dojos in 1
It seems to me, that you have two kinds of people there now. Those that want to continue to learn and practice the way they have been, and don't want to change. And, those that have an open mind and are willing to try something different. If merging is not happening, then why not treat each other as two completely different MA. Would you be having a problem if the other group was doing Judo, of Karate? Probably not. So for those who do not want to change, then look at the other group as a completely different MA. You don't have to participate if you don't want, or you can keep an open mind and maybe, just maybe you will find that even though the other group is different, they mau just have something to offer that you were unaware of. It's a great opportunity, to learn from the differences rather than shut yourself off because of them.