Agreed, Gil has shown the ability to open his Gate of Babylon portals anywhere he wants he could just open a dozen portals around her at point blank range and shread her from all angles and she would have no counter to that and I'd like to point out that Gilgamesh with Unlimited Mana is equally terrifying so both would have unlimited mana for their Noble phantasms expect the more Gil uses Ea at full power the more likely the world will end as in Strange fake that would have happened if Enkidu didn't use their Enuma ELish to put the world back together, I'm not even being hyperbolic, word for word that's what happened,

Artoria with unlimited mana can fuel Excalibur for lots of blasts, but that isn't an issue, Gil has defenses that can block Anti-Fortress Excaliblasts, but Artoria is stuck being endlessly bombarded by weapons, spells, and whatever else Gil feels like using

True hell he has Fire, Lightning and Ice in his Gate of Babylon, so he can just fire random bullshit and she gets hit with random effects, curses, effects, poison or whatever he may have.

He has all the shit they've given him in Strange Fake, all the random stuff from Prillya, just an armory of fun and pain

I honestly want to see him use Hades's Cap of Invisabilty more, because one it looks cool as hell, two it's useful as hell he could just sneak up behind her summon a sword and cut her head off. but this man can already do some crazy bullshit by himself his Caster self straight pulled of what he claims is Prenasce concealment EX, of course we don't know if that's true but still the man is a walking counter to all servants.

Power creep has made people forget that the servants in Fate/Stay Night are all supposed to be VERY high tier. Like, Artoria is supposed to be one of if not the strongest Saber, Cu, while weakened by not being in Ireland, is an incredibly efficient and dangerous Lancer, EMIYA took 6 of Herc's lives without using UBW to the point that Herc respected him despite being under madness enhancement, Medea is one of the best Magus in history, Medusa is a serious issue if she, you know, has more than 3 energy, fake Sasaki is freakishly skilled with his sword, Cursed Arm can instakill you if he touches you, and yet Gil is decidedly the strongest in the war by a sizeable margin.

That is very true, we know that if Heracles was summoned in Greece he would have truly been unstoppable in the war expect by Gilgamesh who could still bea him, If the war was in Ireland I have no doubt Cu would be running through everyone in the war(Artroia, EMIYA, Medusa, Heracles, Sasaki, Medea)not only would he gain seaven more Noble phantasms and fame boost but he nearly killed Artoria the first time they fought, she only lived because luck,plot and her instinct skill. Soloman himself, the King of Mages, has said that Medea is one of the best at magecraft, Gil is someone were when he's not held back by plot it doesn't matter how strong someone is they will lose to him, he shredded Medea, fought Sasaki and Kuzuki back to back with a flawless victory, killed Cu and Herc and has overpowered Artoria so badly she needed Avalon to win, he's the strongest Heroic spirit for a reason it's why he has to be held back by the plot.

Heracles was beaten by Altria when she had enough mana for excalibur or even a charged up caliburn.

Also that Heracles was significantly buffed as a servant and had madness enhancement

He's strong asf but he's not on the level of the best servants