Ah, Base Thanos. Got it. Also, never said Thanos was EVER a 1-C being. I'm just saying that, if you were to actually beat him, then you'd need a High 2-A Power to ACTUALLY defeat him. Also, most of Thanos' loses occurred because he was either cocky/arrogent, or he wanted to lose.
Other than that, MCU Thanos' SNAP destroyed half of the Universes' Population. And the MCU's pretty much based off the Comics (Mostly, that is. Though, of course, it doesn't follow the story of the Comics in the same order). So, Thanos' Power in the MCU should be about the same as it was in the Comics. And Comic Thanos had Infinite 4-D Power/Low 5-D Power. Hell, he became one with Eternity in the Comics. I don't think MCU Thanos is weaker than Comic Thanos. And that's due to Thanos not showing the Infinity Stones FULL POWER yet, like...AT ALL!
He only destroyed half of the Universes' Population. That was it. He went easy, and did an easy job. That was not trying with all the Stones. If anything, i'm just predicting at this rate. For all I know, he could be weaker. And if so, then sure, i'll accept that. However, as it stands, I do think that MCU Thanos is supposed to have the same Power as Comic Thanos (Both with/without the Infinity Gauntlet).
But yeah, no, Base Thanos would still win in my eyes, mostly due to Sans' crappy range in his attacks.