Fisherman,
Does the Bible teach predation before the fall of man as you interpret the Bible ?
Your question (Unless I've misunderstood) was whether JW teaching is consistent. Admittedly, I've picked a low hanging piece of fruit here, but it does provide a glaring example of inconsistency.
For example:
What was the food of the animals? The inspired record states: “To every wild beast of the earth and to every flying creature of the heavens and to everything moving upon the earth in which there is life as a soul I have given all green vegetation for food.” Or, as Today’s English Version of the Bible puts it: “For all the wild animals and for all the birds I have provided grass and leafy plants for food.”—Genesis 1:30. (Awake! October 8, 1982 p. 10)
"The natural “sanitation squad,” made up of insects, microorganisms and larger animals, has done other things that man would never have been able to accomplish. These scavengers work to clear the forest floor of the debris of dead branches and trees. They dispose of the carcasses of dead animals. They thus prevent many devastating forest fires and much pollution and disease." (Life Does Have A Purpose p. 94)
Obviously it's inconsistent to praise the functioning of earth's ecosystems as evidence of a wise creator in one publication and condemn it as the unplanned consequences of an original purpose gone awry in another.