Answered by Shaykh Amjad Rasheed
Is it permissible for me to pray the Friday prayer behind a Hanbali imam who is leading the Friday prayer before the time of Dhuhr comes in?
It is not permissible for a Shafi’i to do this unless he juristically imitates (Ar. taqleed) the one who permitted it — this being Imam Ahmad (Allah have mercy on him) — while being careful to follow his school in the remaining regulations of prayer.