Links are just a suggestion
LN: contains consecutive double letters
SO1: FN is related to an opera
https://www.behindthename.com/names/description/opera / MN is three letters long
SO2: FN starts and ends with a consonant / MN is popular in the US
https://www.behindthename.com/names/tag/never_out_of_the_us_top_1000
S1: FN contains an english word, but is not a word name / MN is same amount of syllables as FN
S2: FN is a place name
https://www.behindthename.com/names/gender/masculine,unisex/description/place / MN is often considered ‘old-fashioned’
S3: FN is a one-syllable word name / MN contains the *ae* pattern
https://www.behindthename.com/names/gender/masculine,unisex/pattern/*ae*