The Troops In The Centre of the March (Numbers 10:18-20).
‘And the standard of the camp of Reuben set forward according to their hosts: and over his host was Elizur the son of Shedeur. And over the host of the tribe of the children of Simeon was Shelumiel the son of Zurishaddai. And over the host of the tribe of the children of Gad was Eliasaph the son of Deuel.'
These were then followed by the tribe of Reuben, along with Simeon and Gad, under their respective chieftains. The Dwellingplace of Yahweh was being well protected.