[@MegaOscarPwn] I posted a link with ranks.  And now I've fixed it so it works.  The American equivalent seems to be Private First Class, but I'm not familiar with the specifics.  Unfortunately, [@Oak7ree], Finland is not on the list.  [url=https://en.m.wikipedia.org/wiki/Company_(military_unit)]This page[/url] has commanding officers and the units they generally command, but it's all ranks in English.  [url=https://en.m.wikipedia.org/wiki/Ranks_and_insignia_of_NATO]This one[/url] mentions various ranks in English and compares between air, land, and water.  There's some variation from nation to nation and between the three divisions, but the basic idea is the same.

My understanding is that a lance corporal would indeed lead a fireteam, but a full-corporal would outrank him slightly?  So lance corporal, corporal, and then in some armies there seems to be something like corporal major or a super-corporal, which is a slightly higher rank.  It's divisions within the rank, I guess.