Seems like you are conflating nullify and counter forces. The pool table does not nullify gravity attracting balls together. The attraction at that level is smaller than friction. Using placeholders to explain unexpected results, like dark matter, leads to hypotheses that can be tested.

You can start with a new set of theorized forces, but you have to now explain everything that is conforming to the old set. That we keep on observing exceptions is testament to the idea that science allows any hypothesis to be tested and forwards the saying : There is no settled science.