One Last question on routing

[tinkthank]

Sorry, I will stop once I understand this:


Lets say provinces A, B and C all border one another, province D borders A and B.
Nation Spam owns province A, nation Schleim owns provinces B and C.
Schleim hits province A with ghost riders, which gets repeled, although some of Spam's units rout.
Spam moves his remaining army into B from A the same turn, out of which B moves his army into D, cutting off Spams only supply line. Both Armies win their battles, although a small number of both victorious armies rout.
Spam still owns A, and now owns B as well, while Schleim lost B and gained D.
Now the routed units of Schleim's victorious troop from the battle in D will have nowhere to rout to (C was their only supply line to B), and hence just disappear -- right?
And the routed troops from the magic Ghost Riders battle in A -- can they have routed to the newly gained province B?
But what if Spam was not victorious in B, but rather lost half that army, while the other half routed -- since these routed units still have A to return to, they can rout back to A. But what about the routed units from the magic battle -- they have no where to go but A. Can routed units "return" "back" to A, or do they go lost?