Eirik sits next to 4 phonetic neighbors — Erik, Eric, and Erick are the closest matches by sound. Most share Eirik's Scandinavian cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"eternal ruler, ever powerful"
"son of Agnes (pure, holy)"
"earth, key"
"autumn"
"wise army, counsel-warrior"
"short form of Reinhard (pure heart) or Reinier"
"Jehovah is God"
"plant that grows in moist places"
"elf army (alternative theory)"
"peaceful, gentle"
"one who carries the treasure"
"son of Erik"
"divine meadow"
Similar sound: These names share phonetic patterns with Eirik — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old Norse origins, giving them the same cultural heritage as Eirik.
Rhythm: Eirik is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.