Why were the number of fighting men counted in the Bible and not the population?


The sons of Tola:
Uzzi, Rephaiah, Jeriel, Jahmai, Ibsam and Samuel—heads of their families. During the reign of David, the descendants of Tola listed as fighting men in their genealogy numbered 22,600. 1 Chronicles 7:2
All these were descendants of Asher—heads of families, choice men, brave warriors and outstanding leaders. The number of men ready for battle, as listed in their genealogy, was 26,000. 1 Chronicles 7:7
The sons of Bela:
Ezbon, Uzzi, Uzziel, Jerimoth and Iri, heads of families—five in all. Their genealogical record listed 22,034 fighting men. 1 Chronicles 7:40
            Keeping genealogical records back then were to record the family lines for inheritance reasons and property rights.  For the line of Judah, they needed to know who the next king was and for the line of Levi, which men served as priests in the temple.
            Another reason they counted the men was to keep track of the number of reserves on hand in case of war, which happened pretty frequently back then.  Each of the tribes had their people they could call up in times of threat.
            So this number was for security and safety.  Recording those numbers and making them public would deter outsiders from attacking.
            David got in trouble for counting the fighting men for the wrong reasons.  He wanted to know his power and he trusted in the numbers instead.  We must examine ourselves and why we count numbers too.  Do we trust God more than we trust the numbers?