I agree with George. If you want wood to work now, I'd only choose one of the trees and leave the others until the sap starts flowing in spring so their bark comes off easier.
It's been my experience that different woods take to speed drying differently, with some warping more easily, some checking worse and others holding up quite well. Winter-harvested hickory seems to hold up well to speed drying in my experience, and it can tolerate some back violations associated with cutting the bark and cambium off. It does take longer to dry though, since it's so dense. I've never had luck speed drying elm, it always warps for me, even when clamped to something to keep it straight. I'd cut that tree in the spring, split it as best you can (elm is a beast to split), peel the bark, seal the back and ends, and leave as a non-bending stave for a couple years to let it dry and season slowly.
But that's just me. Feel free to experiment, and let us know how things turn out.