Yet, understanding of the critical mind and wise discrimination can be a potential illumination.
One can start with a comparison between direct experience and abstractions related to doctrine and scholarly approaches. My understanding of Buddhism is that it is not a religion, despite how some insist on making it so or framing the teachings in ways that bring in terms like "theological" where they don't seem to apply. In a teaching where the founder claims no godhood, nor does he expect you to simply believe what is taught without careful examination and testing for proof, how can Buddhism be, at its core and intent, be religious as we understand the term in the West?
My understanding is that the philosophical relationships and arguments between the various schools are the smoke from the fire of the central tenets. Those tenets are centered on the practice of nothing more or less than direct realization without mediator and the rest is merely either a by-product of ignorance or wisdom in relationship as abstractions "about". Anything about what is can be satisfied by direct awareness of the Moon that the fingers are pointing to. Some fingers might point to abstractions and more illusions, yet, that can be useful.
It is rather easy to conceptualize from afar about what the various schools are and how they interact, yet one would find more insight by actually living in the context of those who live a life as nuns, monks and teachers in community. We may all realize that the dynamics of human interaction can be a challenge where living what we believe, even know, is put to the test.
From our vantage point, what might have significance is not just the show going on between various flowers and weeds in the field, but the essence of the beauty, the nectar, the color and the realization, the vibrancy and clarity of the life that may be understood uniquely by each one of us. It is a path, no matter. Then, it is also a pathless path. Then it is neither. Ahh!
To consider the various schools of thought as aspects of one mandala allows us to apply insight and wisdom to those relationships, just as we do in our daily life of practice, living and experiencing. If every part of a mandala was the same, it would simply be a bland circle; a disk with simply an inner aspect and an outer. The mandala is a fitting metaphor with which we can expand our perspective with acceptance and gather the delicious fruits of Awakening to what he are all along.
Best wishes for well-being on your journey.