Assault is the way I see one of the best situation to play the game , but if its possible think about this setting
I think it would be better if the defenders 3-3 on both sides of the bridge so you can start the battle in the village. now you create a defence spot around the tower. And whit this setting defenders can choose if they run to the tower ore make it assault already difficult in village.
Assault can slip trow ore around the defence line and go to tower. but you do not know what you can find there is the extration point whit ore whitout defence players.
And a little more obstacles on the bridge if possible its to open in my opinion!
Negatieve point of setting of Assault like you described in above picture :
If you led defence players on the tower they must wait there till assault is comming on bridge (Its not actieve the guys that start on both sites of bridge they have the best of the game) they kill the assault and the guys in tower diddent see nobuddy!!!!!!!!!