Les nains sont forts en général, mais la faut voir qu'en japonais il ne dit pas nain :
小人 is literally "small person." That's all. They're clearly Lilliputians from Gulliver's Travels, but he couldn't very well use Lilliputian because it's specific to that fictional canon. Dwarf and gnome are both reasonable translations.
Just confirmed: The word used in Japanese translations of Gulliver's Travels for Lilliputians is just straight up kobito (小人), the same word Oda chose.