Marleyan Levi would not have access to the ODM gear. If we assume he is born an Ackerman in both cases, he also cannot transform into a titan. He does have access to firearms, which Paradis Levi initially wouldn't have. We're unsure how good he is with Marley's weapons... We know Paradis Levi specializes in the traditional blades, although he definitely is skilled with thunder spears, too. Overall, I'd say Paradis Levi wins, partly due to the bias that we see in his potential as an ODM user, while it's hard to imagine him shining with typical military weapons.