Uh ok. So the philosophy behind the reason for the document means little to you . . . ok?
Fact: The LXX was translated FIRST in the first five books of the OT . . . and then picked up later SEVERAL times BY DIFFERENT MEN THAN THE FIRST . . . and translated with DIFFERENT translation strategies and convictions until the whole scope was done over 200 years (give or take).
FACT: the first five books are WELL DONE . . . and the quality tapers off from here to BAD in the latter portions of the text.
FACT: It was done, not because some prophet of God came along and spoke for the people ordaining this text (laying some claim to divine inspiration), BUT BECAUSE the whole of the Jewish world was becoming HELLENIZED and people couldn't read and understand Hebrew anymore, so any semblance of religious affinity needed to be maintained . . . oila . . . the decree of King Ptolemy II Philadelphus (309-246 CE/BC), A PAGAN incestuous chap, for the furtherance of his library . . . or (if the King account is taken as non-historical . . . but there is really no reason not to), the decree by someone to conscript this task.
These are the well attested to FACTS (save for the possible dispute of the King's conscription).
So while many books in the OT are practical . . . THEY ARE DONE UNDER THE PHILOSOPHICAL ASSUMPTION OF THE DIRECT INSPIRATION OF GOD THROUGH HIS HOLY SPIRIT . . . and are thereby considered the VERY WORDS OF GOD. The philosophical assumption underlying the LXX is NOT THE DIRECT INSPIRATION OF GOD THROUGH HIS HOLY SPIRIT . . . but IS the MUNDANE goal of common access to that which IS GIVEN BY THE DIRECT INSPIRATION OF GOD THROUGH HIS HOLY SPIRIT. Ergo, the translation is not inspired in the same way as the ORIGINAL HEBREW/ARAMAIC of the first writ of the OT.