Grail level growth curve

So some servants have a reverse S growth curve (they get more stats at the beginning and end levels than at the middle). Does this growth curve affect the stats gained from grail levels too? For example, would Cú Chulainn (lancer) (with a reverse s curve) get more stats from level 75-80 compared to someone who has a linear curve (same stat gain throughout) such as Hassan of the cursed arm? Or are stats gained from grail levels separate from growth curves?