[quote=@Oak7ree]
<Snipped quote by Lady Selune>

But using them both as a rank just puzzled me.

I just haven't seen both used at the same time. Here in Finland, for example, corporal (either "korpraali" or "alikersantti", depending on translator) leads a squad, while a lieutenant (either translated as "vänrikki" or "luutnantti") leads a platoon, a company or a similar sized unit.
[/quote]

Over in England (and I believe Canada,) we have different ranks of Coporals.