> Figuring out how the Fate series works is nine kinds of headache in itself
I don't get why people like to overcomplicate this stuff
There's the Stay Night VN, Zero and Hollow Ataraxia
and then a bunch of spin offs you can play in whathever order
anime wise the Saber route wasn't adapted well, so you either start with Zero or Unlimited blade works, after those two Heaven's feel

Figuring out how the Fate series works is nine kinds of headache in itself, but as I understand it, each summoning gives a mythological character who's abilities have been trimmed down into the(variable number, 7 in this case, but I believe the total is something like 24, not counting parodies) different classes, each with it's own specialty. The true names are a spoiler usually only in-story, as fans can usually figure it out quickly(and non-fans don't really gain any insight from learning it).

Gilgamesh is outside of Stay Night's summoning ritual(a hold over from Fate: Zero). He is not acting as an Archer for this story, even if he's holding over his Archer class abilities(and looks) from his previous appearance.

And to resolve this, in story, while everyone else gives only their class, Gilgamesh in Fate:Stay Night introduces his class as Gilgamesh. The show credits refer to the other servants by class, even after their identities are revealed, Gilgamesh is referred to as Gilgamesh.

You should expect spoilers if are looking into the sprites, duh

Given every other piece of media Gil is in just calls him by his name and this game is pretty ancient by internet terms... I see no reason it should be hidden.
I don't think many games on this site strive to preserve spoilers.

I wonder... Should the servants have their true names listed or would that be giving away spoilers? I mean Gil's name is shown front and center, yet he answers as an Archer.