Kobold Variants

Investigating the art of TSR era Dungeons & Dragons is a deep rabbit hole and I expect I'll be delving into it a great deal over the next few weeks. Apologies in advance to those of you who don't find this sort of thing nearly as interesting as I do. That's why I'm briefly going to return to the subject of kobolds.

Lore Suto reminded me that Jim Roslof did some illustrations of kobolds for AD&D module A4, In the Dungeons of the Slave Lords. Here they are:

These kobolds look very similar to those he drew for the AD&D Monster Cards in that they're, for lack of a better word, more impish in appearance than the small, scaly dog-men of the Monster Manual. Also in the same module is a second depiction of a kobold, this time by Erol Otus, who had previously drawn a kobold for the Tom Moldvay Basic D&D rulebook. The kobold above is actually dead, reanimated via myconid spores. Even so, its appearance differs from that of Roslof's kobolds earlier in the same module. Otus's depiction is closer to those in the MM, in spite of the fact that he had previously drawn a kobold for Basic D&D with different characteristics. It's fascinating and makes me wonder about the nature of art direction during the days of TSR. Were all these variants the result of a conscious policy or was there not much direction, leaving artists largely to their own devices?