Sorry, never heard of either.
I would avoid any Chinese product, even the Marathons. Why take the chance?
Go with Maxxis M8008, great reputation.
And yes, we will get the Goodyear apologists claiming that Maxxis is made in Thailand, and that Thailand is no better than China, but that is simply not supported by the facts.
And the C-rated tires have enough load capacity for your camper.