John Gill Commentary Numbers 1:45

"So all they that were numbered of the children of Israel by their fathers` houses, from twenty years old and upward, all that were able to go forth to war in Israel;" — Numbers 1:45 (ASV)

So were all those that were numbered of the children of
Israel
Of all the tribes, excepting Levi, that is, all the sums of the number of the children of Israel; all put together made the sum total given in the next verse:

by the house of their fathers, from twenty years old and upward, all
that were able to go forth to war in Israel ;
all in every tribe, family, and house, that were above twenty years of age, healthful and strong, and fit for war.