This wild fantasy isn't particularly wild, it only relies on Yankes adding the new multiple soldier types functionality from the main branch, as well as a lot of work. It's not really revolutionary either, especially since I've been talking with Dioxine and he expressed interest. But somebody has to say it: multiracial pirates.
According to the lore, there are several basic mutant strains on Earth, or in other words consistent mutant types or "races". One of them are ubers, which we already have, but there are other strains too, and there's nothing preventing them joining the crew. It should however be noted that ubers are generally the best pirates Earth has to offer (stat-wise), so some sort of mechanics would have to be introduced to make these other races viable.
HUMANS: pureblood humans are the same as those who serve in the factions. Their basic profile is similar to X-Com agents', but they're generally better at melee (it's a tough world).
LAMIAS: a stable strain of centauroid mutants: half-humans, half-snakes, created in Star Gods’ experiments. With natural armour, they are tough (comparable to ubers), as well as brave, but not very good at psionics. They have good melee, firing and throwing accuracy, but are somewhat lacking in speed. They can use decent heavy armour, but it must be made specifically for their body plan.
BRUTES: big mutants, strong and resilient. They have good strength and health values, but not as much armour as ubers. They are too big to wear armour for ubers and therefore need their own designs, which are less diverse but analogous. Brutes heavily augmented with cybernetics and bioengineering for combat are called mutons.
HYBRIDS: similar to humans, but they have lower health and a bit less strength. They are good psionics though, and they have excellent night vision. They can use the same armours as humans.