I think that’s a very important point. If you “balance” the EQ like you describe but you boost a frequency band that our ears are more sensitive to and lower a band that we’re less sensitive to by the same amount of dB… The mix might still sound louder than before.
So don’t worry too much about the numbers and heed the great advice given in this thread.
I also try to say “look it up online” as much as possible in stead of Googling it.