Sectarian or not is a matter of how one interprets the subject. When one says the other is sectarian, one has already associated himself to be different. And that is one of the problem In this world now, we are actually all the same, we all want the same thing,,....happiness, don't we?
In the religious world,I believe all religions teach their practitioners to have the same basic good human qualities.......kindness, loving, compassion,forgiving, patience, tolerence, acceptance, peace, harmony..................and so on and so on. Whichever religion suits you, that is the path and way you choose and hope that it will lead you to develope those qualities to true happiness.
Buddha Shakyamuni teaches 84000 methods to achieve liberation, because Buddha Shakyamuni already knows the diversities of our human delusions. So it is like all roads lead to Rome, you choose which one you find suitable. I don't see any sectarianism in achieving happiness and liberations, it is just different methods to suit our diversities of appetites. We will all have a full stomach at the end of the meal, and likewise, true happiness at the end of our spiritual journey.
All problems lie in the fact that we think we are right.............and you are wrong, we are better........ and you are worse.