Hence why I said "excluding robot-mode limbs", leaving the limbs specifically based on an arthropod rather than a humanoid.

 

Think of it this way. They didn't scan arthropods, they're simply called insecticons because from a human standpoint, there is something insectoid about them. Airachnid isn't considered an insect, we are saying she is considered an Insecticon because of her arthropodic traits (all of which you said), color scheme, and ability to control Insecticons. So, bottom line there isn't any more wrong with an "Airachnid" being an Insecticon as there is with Laserbeak having reptillian traits in DotM. They aren't really animals, they are aliens with an animal motif.

 

They are in the same continuity family the same way the G1 cartoon, comics, and Beast Era are all in the same continuity family. Get over it.