How do you draw with precision when using vertex paint? With the current settings i can’t draw color as the reference look.
Vertex Paint relies on geometry, so you need a lot of geometry to allow you to paint precision markings. Texture Paint uses UV mapping to align mesh to an image texture where your paint can then be as precise as the value of pixels per face.
How do you get more geometry? Increasing the vertex count make modeling more time consuming.
Applied subdivision modifier or manual subdivision - but either way, your question is how to get smooth vertex paint result. Depending on what your model needs, you can add definition to where you want the detail to be OR you could use Texture Paint and UV mapping to arrive at a very nice result without the density requirements.