Most terrain blending you see out there is done with lerp nodes and using only a single height map. The result is that the blending between two textures is inaccurate. One of the textures and it’s height values is not being used. What you want is that both your textures and their height maps interact with each other. So at the point of intersection the shader looks at which part is highest, and will prioritize those area’s over lower parts.
A popular article about this is the Advanced Terrain Texture Splatting from Andrey Mishkinis
To make it easy during production, we have a pre-built Shader Function that does this calculation. Now you can simply drag it into your shader graph for you to jump straight into building the core purpose of your shader. From there you for example can create a vertex color painting setup for terrain blending. Or ofcourse any other setup that you might need.