Warfare placement

when my guild has to attack a city and defend 1 in guild warfare i assign 15 to defend 15 to attack but i get 6 defenders 24 attackers i have never had players in the cities that i assigned . No my VH don't touch the assign page. i was on beta as host Server 2 as host i never had anyone where they was assigned to go it has caused us to lose cities a few times. like tonight on Heart of Dragons server i had 11 to defend 1 city 21 to defend the other then city that was to get the 21 players got 5 causing us to lose the city