Question Which approach is the correct method for applying/blending textures on a terrain tile?

Hi all - I'm now plunging into adding textures to a unity terrain tile based off elevation programmatically. There seems to be 3 (?) approaches to this, all different, and I'm not quite sure which one I should pursue.

1) create a splatmap and assign it to the terrain, although I read somewhere that this is a depreciated approach.

2) Sebastian Lague's approach is to assign textures in an array, and then have a shader use these arrays to apply and blend the textures. Which, granted, I have currently been unable to get working, even with a URP shader.

3) Or ... do I assign texture layers to the terrain tile (i.e. not a programmatic array per se, but actual terrain layers) and then use a shader to blend them according to height?

This is a completely new subject to me (so lots to learn) and I will admit to being a little overwhelmed and needing to focus my attention on 'the correct way forwards', as the various approaches is confusing my learnign endeavors.