No wouldnt want this it would badly affect on the game balance. Novices would get attacks more often only to steal their troops and need to fight against their own units. The possibilities are smaller to get troops of high lv players, autohiding catacombs take the chances to get the troops effectly. If they loose the troops in the own castles which building have the higher priority ? Infirmary or the teleport which is bringing troops in the enemy castle ?

No good idea to have such effects.

i agree with both the comments.. is this trying to implement the major failure with BG where 30% troops used to some back one again.. then obviously NO

why not just make it so people can donate units to other people. Huehuehue.

No. Very bad idea. Newbies could spend a week building up an army only to have them stolen by high level cowards. Then same again next week. Then quit game.