If there is one thing we all should be dogmatic about, it is in rejecting sectarianism.
Wherever you stand, whatever you practice, whatever you read, whatever you understand: reject sectarianism. It is unwholesome. It is fruitless. It causes division and harm. It is to be abandoned.
It is almost never based on close engagement with texts, nor sufficient historical knowledge, nor realisation.
So ask yourself 'what is it based on?' and give it up. There is no place for it.