I've gone through admittedly just a few RT leagues and found Cousell, Posednik and Woodward all available: they are all on the same side of the trade. Still seem fair?

Renteria is just 3 years removed from being a top 5 vote getter for MVP. Posednik? As for upside, if they both return to top form who has the better year?

No, not fair. Less tilted than before, but the see-saw still has one side with it's feet on the groud.