I was curious and found this rationalisation: https://www.mentalfloss.com/article/76007/why-it-eleven-twelve-instead-oneteen-twoteen https://www.mentalfloss.com

I was curious and found this rationalisation: https://www.mentalfloss.com/article/76007/why-it-eleven-twelve-instead-oneteen-twoteen https://www.mentalfloss.com/article/76007/why-it-eleven-twel... It's pretty hand-wavey but still interesting speculation.