Great idea but I think you should be somewhat restricted to have had suffered some losses first (say ~50%) and you would need to retreat every remaining unit to the deploy area.
In addition it would be even better to have dynamic campaigns with different follow-up szenarios for different results i.ex. "Major Victory", "Minor Victory", "Minor Defeat", "Major Defeat" and maybe even "Draw".
That would be really great but i somehow doubt we will see this (soon).