It depends on the length of the stems. You might have to do a little bit of trig to know for sure. Whether you gain three or 3.5cm really doesn’t matter though.
if you have halfway decent health insurance, it should cover a bike fit. Pain during physical activity is something that insurance companies are actually motivated to help you with, because it increases physical activity.
sometimes bringing the stem closer is as effective as raising it, and in my own experience, changing saddle position did more to eliminate hand pain than anything I tried with the bars, and I tried a lot.