Medical tent/heal non killed troops from previous attack

All surviving members of being lost go into a medical camp/tent to heal. Upgrades allows more troops or quicker heal timetime

you must add more detail for this to even be considered

Unfortunately, I doubt remaining alive troops will ever return to the village. That is because people would just use strong armies in lower leagues, where almost no troops would die. This would result in a continuous farming with no resources spent on creating new troops.
Also, one of the worst scenarios when this would be too OP is the Queen+healer strategy, which would greatly benefit from this attack strategy.. and in fact not only this one, but the lower level players could also highly benefit from the Giant+Healer.