Who is Reuben's tribal head upon entering the promised land?

Question

In Numbers 1:5-16, we see the appointment of the princes or chieftains of the tribes of Israel. In verse 5 we clearly see the tribal head for Reuben:

And these are the names of the men that shall stand with you: of the tribe of Reuben; Elizur the son of Shedeur.

But in Numbers 34:16-29, the listing of those to apportion the land of Canaan does not have anyone for the tribe of Reuben:

19And the names of the men are these: Of the tribe of Judah, Caleb the son of Jephunneh. 20And of the tribe of the children of Simeon, Shemuel the son of Ammihud. 21Of the tribe of Benjamin, Elidad the son of Chislon. 22And the prince of the tribe of the children of Dan, Bukki the son of Jogli. 23The prince of the children of Joseph, for the tribe of the children of Manasseh, Hanniel the son of Ephod. 24And the prince of the tribe of the children of Ephraim, Kemuel the son of Shiphtan. 25And the prince of the tribe of the children of Zebulun, Elizaphan the son of Parnach. 26And the prince of the tribe of the children of Issachar, Paltiel the son of Azzan. 27And the prince of the tribe of the children of Asher, Ahihud the son of Shelomi. 28And the prince of the tribe of the children of Naphtali, Pedahel the son of Ammihud. 29These are they whom the LORD commanded to divide the inheritance unto the children of Israel in the land of Canaan.

Was this a scribal error or what was the reason for a tribal head of Reuben not to be listed? Who was to head the tribe of Reuben?

Answer 1

Let's see the context:

Numbers 34:13 Moses commanded the Israelites: “Assign this land by lot as an inheritance. The Lord has ordered that it be given to the nine-and-a-half tribes, 14because the families of the tribe of Reuben, the tribe of Gad and the half-tribe of Manasseh have received their inheritance.

In Numbers 34:16-29, two tribes are missing: Reuben and Gad. Moses wrote only about the ten tribes inheriting the land west of Jordon.