this is how the original XCOM worked, so at least it's not a new issue.. : P
When this happens to me, I usually just stand on top of the two unconscious units and revive one, exit the med screen, re-enter the med screen, and revive the second unit. Once the first unit is revived, it will appear on an adjacent square and will unblock the second unconscious unit.
It's a strategic limitation, true, but I'm not sure if it's worth fixing..