The feeding quantity is a guide. Babies can take different quantities feed to feed and day to day. They are a little like adults, some of us eat more and some of us less. Trust your baby to take the amount that he or she needs. I agree with tracking wet / soiled nappies and also weight gain. Hope all goes well :)
If weight gain is consistent and diaper output is normal, I wouldn't be concerned about exact number. If a baby is breastfed how can the mother even know the exact number, but breastfed babies can still grow up fine. Some PD's don't care about numbers at all 😁
What PD suggested or feeding table on Formula tin is only guide Feed newborn by demand