In most cases it depends on the amount of Pothos growing in the tank compared to the amount of fish.
If you have a well stocked tank 50 or 100 gallon tank with only one or two small stems of Pothos in it, I don't think you will ever see a significant reduction in nitrate.
The amount of plants that will make a noticeable difference, will need to be minimally double or triple that of the weight by volume of fish.
The word overkill, does not does apply when attempting nitrate reduction.
If you look to nature, the amount of vegetation weight compared to animal weight indicates the way.
The shot above was taken on a small tributary of the Magdalena river in Colombia.
Below vegetation surrounding a small pristine steam in Panama.
Even with my 6 ft tank planted like this, I still do every other day 30%+water changes to achieve my nitrate goal of 5 ppm or less..