The first Rashi of Tazria cites a Chazal which addresses the connection between the end of Shmini and the start of Tazria. The idea is that just like in creation animals preceded people, so too in regard to their laws of purity and impurity animals come first, followed by people.
Rav Shlomo Yosef Zevin in LaTorah VeLaMoadim pauses at this Rashi and points out 2 similar Rashis. 1) When Yaakov meets Eisav and organizes his family. 2) In reference to Bnot Tzolfchod. He also points out that Shabbos follows the rest of the week as well as other examples of saving the best for last - the concept of "Acharon, acharon, chaviv."
He then points out that the opposite concept is not a foreign one - that best comes first. The first as chosen or special is a well known idea (that's caused pain for many youngest siblings) and exists in traditional Judaism prominently in the concept of Bechor/Bikurim.
Rav Zevin refers to the following medrash on Breishit: When we live up to our potential man is told by G-d that all that was created is for us and that's why we were created last. But when we stray G-d reminds us -"Even the gnat was created before you".
This idea helps put Rashi into context. It's true that last is best. But only if last is elevating what came before it, transcending it. But when last misses it's spiritual calling, then it's first come first served ,whoever was physically created first is more esteemed, and last is last man on the totem pole.
May we be blessed to transcend animals and our animal dimensions and be worthy of being considered the best of G-d's creation.
Rabbi Neil Fleischmann