That is a fact. Each ethnic group had their own language and the languages of man tribes were all based on known {European} tongues. Hobbits spoke a language based in Middle English and the Rohirrim spoke based on the older Anglo Saxon, so they had some commonalities that each understood. Of course the dwarves were not 'men', maybe that is why Tolkien moved to the eastern far north and the Eddas.
Gandalf means 'Wand Elf' even though he was not an Elf. I forget why Tolkien decided to do that. In Elvish he was named Mithrandir - the Gray Pilgrim.
It was quite a linguistic exercise to write the Dictionary, took a few years. Of course the Elven tongues were of his own making - and they evolved over the years, adding some extra challenge. Tolkien started writing his 'Tales' around WWI and time changes things.
“Olorin I was in my youth in the West, that none now remember.” Or words to that effect. :^)