Tibetan Buddhist history seems like it was filled with a lot of infighting?

I'm still new to this path, but I am feeling a little bit put off learning about how the different schools of Tibetan Buddhism used to fight each other for power. I might be very misinformed and am completely open to being educated properly, but it seems insane that the Gelug school got military help from the Mongols to supress the other schools. And the concept of the Dalai Lama was created by a Mongol leader? It seems so silly that Buddhist leaders couldn't create a system where they all ruled Tibet equally using their wisdom and compassion for one another.

Edit: Thank you guys so much for not feeling offended by my question. I genuinely meant no ill will or disrespect and after having this discussion with you guys, I no longer feel put off or disillusioned by Tibetan Buddhism, thank you for the thoughful responses!