Do joules matter? Doubting my move.

Skin type 4 and getting a black ink tat removed from inner forearm. First tx was w/ Quanta Q+C @ 5mm spot size-2.5j, 2nd tx same machine-3.4j. Was getting decent results, but research led me to switch providers because I found a facility w/ Piqo4. Found they started me on ns-1.5j, 10mm spot size. Is this kosher? I'm not an expert, but it seems superfluous to start at less than 2j when I was at 3.4j. I mainly chose this machine because I wanted to be treated w/ pico speed. Now I feel set back.