Leviticus could be an outline of the marriage ceremony between God and Israel.  The first years of marriage were no honeymoon.  As the wife ran off and did her own thing, the husband gave more and more warnings until his patience was worn out.  Numbers does have two accounts numbering the people of Israel.  However, the alternative name for the book places the people of God in the desert.  This is the bridging book between Mt. Sanai and the Promised land.

Read an introduction to numbers in a commentary or study Bible.