Old Scriptures & Prophets Vs. Opinions of the Prophet's Companions

In many school's of thought the following sources of religious knowledge are used (in this order - i.e. if the hadith contradicts the Qur'an, the Qur'an overrules the Hadith):

1. Qur'an (Words of God)
2. Hadith & Sunnah (Words & Actions Prophet Muhammad s.a.a.s.)
3. Opinions of the Salaf (Prophet's Companions & the first generation of Muslims around the Prophet)
4. Logic

I agree with all (including the order) except for point 3 (Opinions of the Salaf).  I think this should be exchanged with Prophets and Scriptures of Old:

1. Qur'an (Words of God)
2. Hadith & Sunnah (Words & Actions Prophet Muhammad s.a.a.s.)
3. Old Scriptures & Prophets (Torah, Gospels, Psalms, etc)
4. Logic

The reason for this is simple: 
If the answer you are seeking is not in the final edition of the teacher's book (Qur'an - God's Words) and His newest teaching assistant (Prophet Muhammad s.a.a.s.) did not teach about it - then who do you ask:
A) Other students (i.e. the companions of the Prophet)
B) The old editions of the teacher's books and His old teaching assistants (i.e. the Old Scriptures and prophets)

I think any logical person would choose option B because, even though the students have first hand experience, they are still students and may not have fully grasped the teachings - whereas a teaching assistant would certainly have (since they were chosen by the Teacher to be a teaching assistant).

It is also mentioned Numerous times throughout the Qur'an that the believers are those who believe in what was sent down before (i.e. the Old Scriptures)

Finally, there are examples in the lifetime of the Prophet Muhammad (s.a.a.s.) where he would refer to the Old scriptures if it was not mentioned in the Qur'an and he himself did not know what to do.

Narrated Abdullah Ibn Umar:
A group of Jews came and invited the Messenger of God to Quff. So he visited them in their school.
They said: AbulQasim (i.e. Muhammad s.a.a.s.), one of our men has committed fornication with a woman; so pronounce judgment upon them.
They placed a cushion for the Messenger of God who sat on it and said:
Bring the Torah.
It was then brought.
He then withdrew the cushion from beneath him and placed the Torah on it saying:
I believed in you (i.e. the Torah) and in Him Who revealed thee.
He then said:
Bring me one who is learned among you......
Then a young man was brought. The transmitter then mentioned the rest of the tradition of stoning similar to the one transmitted by Malik from Nafi'(No. 4431).

— Abu Dawood, Sunan Abu Dawood^[11]

Anticipated Responses:
Many people will argue - but the Old Scriptures have been corrupted. How can we trust them? 

My response: 
Whatever teachings have been corrupted - God surely would have mentioned it and corrected them in the Qur'an or through the Prophet Muhammad s.a.a.s. 
Therefore, If the Quran and Hadith are silent on a topic, then there was nothing to correct. 

As long as the previous scripture or prophet does not contradict the Qur'an or Sunnah (there aren't many things) - then it is safe to follow it - just as God tells us to do in the Quran and just as the Prophet Muhammad s.a.a.s. did. 

We were never told to follow the Salaf - and they were human like you and I - and they used logic and better judgment when the Qur'an or Sunnah did not have the answer.  They were sometimes correct and sometimes wrong (This is shown in their differences of opinion).  Therefore, since we are also students - like them, we too should use our logic and judgement (if the answer is not in the Qur'an, Sunnah, or OLD SCRIPTURES)