Fantastical Evolutions

[Sirrocco]

...on the other hand, this is a magic-based world. Throw in a connection to six as a magically significant number, and some secondary subtle magics that can only be done with six primary limbs (and that require only the physical actions, and possibly life, and that are simple enough both in trigger and in effect to be both activated and exploited by lower lifeforms) and *everyone* jumps on that bandwagon. Likewise, a bit of magic in the right places makes a whole lot of kinds of anatomy significantly more plausible.