Your mind works in weird ways, my friend, but I appreciate your active and questioning brain.
So. Let me see
Sacrifice is a common way of creating a relationship with the divine in many cultures.
Animals, especially domesticated animals, have long been a valuable resource for humans and as such, they are also a high quality offering for the gods.
Egyptian offerings were often redistributed to the humans after being presented on an offering table, and not burned at all. In Greece and Rome, parts of the sacrificial animal were usually burned on the altar, while the meat was eaten by the humans. So there may be differences in the way a ceremony was conducted, but the general idea was fairly similar.
In the "Book of the Celestial Cow", it is clearly said that Sekhmet came into being when Hathor fell into a blood frenzy after killing rebellious humans. According to this text, Hathor transforms into Sekhmet.
However, in other texts and hymns no mention is made of this connection between the two, or Sekhmet may be seen as the wilder form of Bastet.
You need to understand that in Egyptian mythology, the limits between deities are not that clearly defined. They constantly transform into each other or get syncretized, or get split up in different forms and manifestations.
