His proposal matched my own ideas exactly, though we never discussed it.
Tips
history
From Gan Bao's 《搜神记》 (Jin dynasty): 二人之言,不谋而合 — the words of two people matched without any prior consultation. A classical template for the phrase's meaning.
usage
Emphasizes independent agreement — two or more parties arrived at the same conclusion separately. Compare with 一拍即合 which stresses quick agreement after meeting.