How are the hokages not at the battlefield already?

[ramzilla20]

maybe when the hokages went on the stone head mountain that was the time when madara felt hashi's chakra

 

[DylanSwerve]

Remember that the time period that elapses in one chapter is like two minutes. The Kage's were DESTROYED. The time passed since Madara entered the battlefield where Naruto was is probably like twenty minutes.