Absolutely. Two particle size methods can be correlated - i've done it - keep in mind there are many, many variables you'll need to control. For the ball mill - how do you control the mass temperature and what is it? how many passes are you using? size and type of media? does it degrade into your product and change it's physical characteristics? do you have a way of measuring the particle size distribution that the ball mill results in, and a way to correlate that to what you get off the refiner(s)? What about residual moisture differences between the mills and it's impact? Are flavor differences important to you?
For the refiners - state of the crown, are you using the 2 roll as a pre-refiner followed by the 5 roll, or independently of one another? Are they hydraulics the same across the different adjustment points?
Does any of the above matter? Depending on what your goals are, they may not. Or they may be incredibly important.