You are quite correct, that very few writers try to explain Behemoth, dealing instead with Leviathan. I also note a heavy tendency to try to say what animals they might have been, whereas the book of Job is dealing with massive, eternal issues of suffering, pain, and God’s justice. Surely we should see God’s comments about Behemoth and Leviathan as His answer to those issues?
Yet some years ago I read this comment by a Christian (using a pseudonym), on a Website where a Q had been asked about this. He dealt with a literal interpretation of Behemoth, what kind of a creature it could have been:
The description of Behemoth matches that of a sauropod. In the Congo,
when indigenous tribes are shown pictures of bears, moose and other
animals not native to the region, they understandably do not recognize
the creatures; however, when shown a picture of a sauropod, they
excitedly recognize the creature, claiming it's about the size of an
elephant and lives in the water, but is rarely seen. So there is the
possibility that it may exist. … Alexander the Great, Marco Polo and
others claim in their writings to have encountered dragons during
their expeditions. "Dragons" were what large reptiles were called back
then. (Leviathan appears to have been some aquatic species of
dragon/dinosaur.) When partially fossilized dinosaur bones are found
containing soft tissue, that could be evidence for them.”
However, a scientist has written about this in his book (below) viewing the biblical account of Job as an early pointer for us to understand the natural world but without any need to delve into taxonomy. He uses the Bible book of Job to urge us to ask different questions, to put science and faith together, to get a better understanding that will give us biblical wisdom. Tom McLeish says in Faith & Wisdom in Science,
“Chapters 40 and 41 of Job sing "in exquisitely detailed praise the
power of two monstrous creatures, the Behemoth and Leviathan
(sometimes interpreted as the hippopotamus and the crocodile, but
textually more splendid and terrible)… this is a 'decentralising' text
that places humans at the periphery of the world, looking on in wonder
at its centerpieces... Although the book of Job is the least
anthropocentric of ancient cosmologies, passing by humans to exalt the
great Leviathan as the pinnacle of creation, still mankind retains a
special place in regard to the potential possession of wisdom. Our
examinations of the Lord's answer to Job has identified the same
unreasonable optimism that the great wisdom questions of nature can
one day be answered... The double Hebraic encouragement to search for
'wisdom and understanding' (the practical and cognitive aspects of
knowing) that we have met in Job and elsewhere resonates strongly with
the dual methodology of experiment and theory, and with the
deeply-lying longing for wisdom that their meeting can release."
This scientist author, who is also a Christian, then considers Behemoth as the climax of God’s response to Job’s human questioning about pain. In one sense Job was asking the wrong question, yet Job’s thread of God’s justice in managing His creation is woven into Job’s disputation. A surprising new picture enters the tapestry – Behemoth. The author says:
“With trepidation, and against the weight of opinion, I am therefore
suggesting that the Lord’s answer is an answer to Job’s complaint –
possibly the only adequate answer. There are five lines of argument
that point this way.”
(1) Creation is not out of control. The way Job and his friends viewed ‘control’ was wrong.
(2) The experience of pain cannot be divorced from the confrontation of human hope and a universe of freedom, and this perspective is foundational to the acquisition of wisdom that deals with matters in extreme tension with each other.
(3) God invites a new relationship with the physical world that leaves behind the irresponsibly polarised positions of Job and his friends.
(4) God’s physical structures are not a sideshow; the failure to acquire wisdom in working with nature hurts both the world and ourselves; there is a biblical ‘creation covenant’.
(5) God’s answer is eschatological. Science affirms that nature matters; knowledge has an ancient history and we need to participate in learning and understanding more. There is to be reconciliation between the human and the non-human, a theme of the New Testament. (Tom McLeish, "Faith & Wisdom in Science", pp110 & 145-6 (Oxford University Press 2014)
I cannot do justice to the author with my brief selection of points but I refer to him for his use of those two creatures to advocate combining science and faith to grasp God’s answers to our oft-misguided questions that can show ignorance on our part which a deeper knowledge of God’s created order could rectify.