because it isn't organic.
Remember their powers are drawn from mystique.
Mystique had her fake adamatimun claws cut off in x1 by wolverine. screamed as it happened.
So no since Mystique's powers are their base- they can not transform to harder, inorganic substances. We're going off feats and not speculation.
This doesn't make me able to call weather Thor or Hulk can beat that last wave that doomed the X-men, but it does limit the Sentinels some.
Not to split hairs here, but this entire discussion is speculative.
Now, if we are going to use the Sentinels as power-absorbing/morphing, then Hulk is out of the picture. Who's to say the Sentinels could not duplicate the anger-powered gamma radiation
mutation that allows Banner to not drop dead?
Not to mention that the Sentinels were shown to absorb and duplicate powers, maybe even share them between one another without being in direct physical contact. (the scene where the Sentinels that kill Sunspot and Iceman is what I'm talking about, these two Sentinels almost seem to share the powers of their attackers and switch them, in order to melt the ice and freeze the fire respectively). Also, they're shown to be able to copy organic material, despite being made from inorganic material. I'd hardly call it "speculative" given the nature of the topic here, to say the Sentinels would not be able to absorb and duplicate the vibranium of Cap's shield, or the Asgardian technology/"magic" from Thor. Though it is a bit of a stretch, considering if they can transmute one material to another, it seems to be kind of wasteful to make Sentinels in the first place. (why not just fly to moon and transmute it into solid diamond?)
Sure, Thor is a heavy hitter, but he does have his limits. He is "basically a god", but he is shown to be stabbed by Loki (Avengers), sweat from exhaustive battle (Hulk fight), and if proven to be "unworthy" (which happens from time to time), nothing more than a human without the power of Mjlonir backing him up.
A lot of this depends solely on what the Sentinels programming defines as "mutation". If "mutant" is based solely on the X-gene, then Thor and Hulk could possibly win in a battle with a relative number of Sentinels. (Hundreds, or even thousands of the damn things is a different argument entirely). However, if "mutant" is can viewed as "meta-human", for lack of a better term, the situation is different entirely.
I think Logan even said at point in the film that Sentinels began to target anyone that may have produced the X-gene, even generations down the line, as well as mutant sympathizers. It stands to reason the Avengers would be sympathizers, and as mutants cannot exist in the MCU, is becomes a matter of who has the most firepower and who can hold out the longest. Judging based SOLELY off what we've seen thus far in film/television, the Avengers had trouble holding New York from Chitari invasion, and the Sentinels are far more powerful than the Chitari.
Conversely, if we assume mutants can, for speculative humor, exist within the MCU, regardless of the presence of the X-gene, then we must define Hulk as a being who poses a mutation, as well as the future Quicksilver and Scarlet Witch as mutants. And if they can copy those powers as well...honestly, do we think Stark has armor to stop Sentinels carrying the powers of Hulk, Scarlet Witch, AND Quicksilver?
Methinks not.
The Sentinels were designed, from the beginning, to be THE threat of the X-Men, the perfect weapon against them, able to nullify their powers (in some cases, copy), and kill mutants. How one defines a "mutant" or "mutation" becomes a concern ONLY when its regards to "Can a Sentinel beat________ Avenger in a one on one fight?" It depends on if the Sentinel views said Avenger as a mutant, or one of their supporters. It could be such a thing as Thor just whaling on these things for fun, but because he lacks the strength to do significant damage (and doesn't sympathize with mutants), he may be literally beating his fists against the wall. Even if he has the strength to destroy them, surely after a few getting zapped and crashed, the Sentinels would view Thor as a threat....drop in a few hundred...thousand, and Thor is toast.
Hulks power derives from a mutation that Banner has. X-gene presence or no, Hulk would be a prime target. Assuming their copying abilities aren't limited to X-gene manipulation, Hulk can't win against hundreds of other Hulks. Even assuming the Sentinels cannot absorb is power, Hulk is not invulnerable/immortal. It'd be a helluva fight, yeah, but Hulk would tire out eventually, revert back to Banner, and be face-blasted into oblivion.
No matter how you shake it, the Sentinels would eventually win out against practically any foe, if for no other reason than sheer numbers alone, short of bringing in some cosmic-level being (Thanos/Galactus), "ultra" mutants, (Jean Grey/Apocalypse/Proteus), or magically imbued beings (Dr. Strange)