FWIW, rackets now are manufactured pretty tightly in comparison to years past.
For example, the well desired and sought after (by some) St. Vincent Pro Staff had stickers on it that gave the weight and balance specs.
Weight/Oz. 11.6-12.3 Unstrung
Balanced 1.0-1.5 in. Headlight
Now you're talking 0.7 ounce weight difference, 4 points balance difference within "acceptable" production ranges for one racket model.
Back when I was getting better, I used to use the Prince Graphtech DB 110. I had one frame that I used all the time. When I started breaking strings more often, I bought another one. The difference in the frames was drastic. Even the beam cross-sections were different.
Now, when I got my Dunlop HM200gs, I bought them around the same time and customized them to match as close as I can. I did this before when I bought Taiwanese Wilson PS85s.
I've also bought some more Taiwanese PS85s since then and there are rather big differences in weight and balance. I just try to compensate with lead tape and such.