How strong would a Saber Hercules be? Artoria Avalon's mats confirm that Marmyadose, Hercule's sword, was stronger than Excalibur. In terms of raw skill, Hercules skills border on the Second True Magic. Nine Lives for example is a normal martial technique created by Hercules. And yet with it, Hercules can strike in a spot NINE times simultaneously. Nine simultaneous attacks compressed into one strike and it doesn't even cost mana. That's insane when you think about it.
Defensively, Hercules should still have Godhand. Which would give him 13 lives and straight up immunity to most attacks and spells in the series. Hercules would also probably have the Lion's Pelt, which would make him immune to any man made weapon.
Speed wise, he should be even faster than Avenger Hercules. Because Fate/Strange Fake states that Archer Hercules > Avenger Hercules in terms of raw stats due to Avenger Hercules rejecting his divinity. Which is crazy when you realize that an Avenger Hercules with "nerfed" stats can keep up with Enkidu, who is one of the fastest servants in the entire series.
Between the Lion's Pelt, Godhand, Marmyadose, Nine Lives, and whatever fucking else Herc has, I unironically think that Hercules may be Grand Servant tier even without a Grand Servant container / body. Hell, he might even be Lostbelt King tier.