Apparently it would have been possible for the Japanese to transport newly manufactured Zeros by train in WWII, except there were no railheads near the Mitsubishi plant. There was no airfield in the vicinity either. So they hauled them 24 miles overland using teams of oxen. When the oxen wore out, they switched to Percheron horses.
I suppose the they could use draft animals to get MIGs to Ukraine, but Polish PETA would raise hell.