When hiders are together they use their cc and just decrease the seekers health. When that happens the seekers just have a little hp and they have to recall every time. For example, if there is alister, blitzcrank, fiddlestick, leblanc, maokai, shaco, amumu, etc, in hiders team, they can keep ccing when fight occurs which makes seekers unable to do anything.
My suggestion is that hiders should not move after they choose a brush to stay. When seekers find them, they can run away, but other hiders cannot come and help unless they come.