While they're accurate (mostly) for things like chickens, turkeys and other dinosauria, they need adjusting for creatures with large infant mortality rates like arthopods and quasi-vermin in general...
Since the latter consideration is more important in terms of gameplay/framerate, it is absolutely correct to adjust the clutch sizes to be similar to other creatures of similar size and role (predator/prey), after taking into account yearly clutch counts and lifespan/maturation.
Back in the original Modest Mod thread, I
begged Igfig to make changes to clutch size
an optional module. The original premise behind Modest Mod was to be, and I quote, "...a collection of vital bugfixes and tweaks that everyone should be able to
use comfortably and
without reservation." Well, I think clutch size is controversial and I am in no way comfortable with drastically altering it. (Sadly, my plea was ignored...
)
A major factor in clutch size for egg-laying animals is the fact that eggs are, potentially, a huge source of food for dwarves. Indeed,
eggs are more important than meat
(if any) or other products
(if any) obtained from butchering.
I just worry that, even if there is a need to adjust for infant mortality to make it "more real", that could impact the animal's usefulness to the point that most players would find it makes certain animals
no longer worth raising - making them decide to raise other livestock instead.
Also, for such a discussion, I wanted to remind that there is a distinction between normal animals and Giant versions. For instance, there are Bluejays, which are so small as to be vermin, and then there's Giant Bluejays, which are large enough to serve as a Mount. But, as far as I know, egg size still does not impact the food value of the egg. (See
Wiki's page on Egg Production)