TP while receiving damage from enemy players

There should be a feature where captains can't tp while they have received damage from an enemy player for the last 5 minutes or so. It is almost impossible to raid and win a map because everytime you try to have a fair fight, a captain summons the whole guild and it is so frustrating that you can't do anything about it. 
I think this will make raids more rewarding because nowadays, you would just jump, try to kill an enemy or two and then gtfo before they summon more players.
With this, you could jump, have a fair fight and maybe even win a map for your city.
Please consider :)