You guys can win h19 only if they quit.
They will not quit probably so you can only hope they will have bad leadership and break from inside.
Its just too big quality advantage on their side, its like real madrid 11 players play against 3000 kinder garten kids.
i would suggest to you guys, make peace with h19, save map. Those who do it at right time will get peace. Others who wait untill there is no point giving them peace, will be hunted.