Hello.

I will be grateful for some help.
1)Does the phrase "a sharp fall in soldier numbers" sound natural (meaning "a drop in troop numbers")?
2)Which word (that or which) is used in the context "he didn't give the exact number of troops that/which will leave the country"?
3)Do you think it's possible to say "to meet personally" and "to meet in person"?
Thank you very much for all your help.

1. ... a sharp drop in the number of soldiers.

2. "that" is smoother.

3. Your second phrasing is better.