Both Sony A7R II and Sony A7R II have Full frame sized 42.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Another similarity between these two cameras is that both Sony A7R II and Sony A7R II sensors lack anti-alias (Low-Pass) filters. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moire occurring in certain scenes.
Below you can see the A7R II and A7R II sensor size comparison.
Sony A7R II and Sony A7R II have sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture.