Be very careful when you attack someone with a beacon tower of level 7 or above, especially if they are a long way away from you. They can see how far away you are and how many troops you are sending. They get a timer that tells them how long until your troops arrive. They may recall their troops or send defenses from another town.
It can be a good idea to send a second scouting party just before your main army hits to ensure you don’t find a nasty surprise when your attack lands. That way if you see he suddenly has a lot of defenses you can recall them before they die. Many times I or my allies have sent a big army only to find that the bad guys garrisoned 150k archers from his allies to help protect him.