By discussion you eliminate the improbable and the problems, they therefore provide solutions whether they be favourable or unfavourable to suggestions posed.
Back to the topic in hand this would make defences way to OP and would ruin raiding, if there were less defences you could do realtime strategies like this as long as both players are online and a hallenge battle system or something but this would be changing the whole dynamic of the game.
Also for the defender it gives them very little window of opportunity, if you have logged off and being raided it is probably because you are tending to more pressing matters.
NO CLAN, Back in Training Camp
Don't feel too discouraged, yes it's not a good idea for the current game but TBH with all the realtime gaming out there I have to say I am surprised SC havn't considered creating a second sister app to CoC to incorporate realtime battles - (perhaps they have and we don't know about it!)
and perhaps that's why it's not yet on the ruled out list...
NO CLAN, Back in Training Camp