Names in Lord of the Rings - hidden meaning?

I'm only referring to the 2 Gondorian soldiers "Faramir" and "Boromir". Did Tolkien use Slavic meanings into names of characters? I certainly "Denethor" does not sound anything Slavic. But after realizing that "mir" meant "peace" or "world" or "prestige/precious". Also seeing the many names it gets incorporated into (Vladimir, Valamir, Brenimir, Casimir, Ratimir...etc) after observing the Eastern and Southern Slavic naming systems. There are many theories regarding the true backstory of Tolkien's work. It struck me when the names "Boromir" and "Faramir" came into mind. Anybody notice it but me?