I would think it's how someone is trying to crack your pass phrase. If they are brute forcing each character, the longer multiple words would be harder, but if they know it's bip39 words, that would definitely reduce the number of possibilities they'd have to test. So in general longer is better.
#40hpw

https://fountain.fm/episode/uObNl8jWzNPqPtpxvXGm