1)
What is the meaning of "va'Tikrav ha'Milchamah"?
1.
Radak citing Targum Yonasan: Those who make the war, drew close.
2)
Why does it mention how many died?
1.
Malbim: This shows that it was unlike nature [that 100,000 fell in one day, and the wall fell on the remainder - verse 30].