The order of the distribution—namely, (1) to priests, (2) to Kohathites, (3) to Gershonites, (4) to Merarites—is in strict agreement with the order…

And the children of Gershon [had] by lot out of the families
of the tribe of Issachar
…

The Levites waited until the other tribes were provided for, before they presented their claim to Joshua. They build their claim upon a very good f…