This explanation comes from the website of HH the Dalai Lama:
“The tradition I follow places a lot of emphasis on Lam Rim (the stages on the path to enlightenment) and it is said that the greatness of Lam Rim lies in, among other things, being able to understand all traditions and seeing that they are not contradictory to each other. I have noticed that when I listen to teachings from other traditions (Zen, Pali, etc.), they all sound like a Lam Rim teaching. On the surface, the various traditions may seem very different, but they complement each other very well ”.
Laying a foundation
“At the same time, Rimé does not mean that you practice everything without having a solid core. All the great Rimé practitioners learned from the other traditions, but kept their own tradition or stream as the center of their practice. As if their own tradition was the main component and the teachings from elsewhere additional parts. My teacher once remarked that Western Buddhist practitioners tend to want to learn about everything, which is good. But it’s about deepening our understanding. When we know a little bit of everything, without deeper insight, we become a spiritual junk heap.”
“The different Buddhist traditions are like stairs leading upwards. One staircase may be Zen Buddhism, the other Theravada Buddhism, and yet another is Tibetan Buddhism. It is useful to learn from all the different stairs, but eventually there will be a time when you will choose one of the stairs Otherwise you will only spend time studying the stairs without ever going up I’m not sure when someone decides it is time to study one particular tradition or movement “To follow is a rather personal decision. People should take as much time as they need to figure it out, but the point is they have to choose in the end if they want to make serious progress.”
HH the Dalai Lama