Why are Imam Ahmad's choices rarely mentioned in Ibn Rushd's "Bidayat al-Mujtahid"?

Ibn Rushd (Averroes) did not frequently mention the opinions of Imam Ahmad ibn Hanbal in his book "Bidayat al-Mujtahid" for several possible reasons, including his reliance on Ibn Abd al-Barr's "Al-Istidhkar," which in turn did not frequently mention the opinions of the Hanbalis. Furthermore, the jurisprudential disagreements were well-known between the Hanafi and Shafi'i schools, and Ibn Rushd was keen on recording their differences in addition to the Maliki school, which was his own madhhab. In addition to this, the Hanbali madhhab was geographically less widespread compared to the other three madhahib, and perhaps Ibn Rushd had access to few books of the Hanbali madhhab.