While Errant has slightly more muscle mass for her size she is still her size. She has to compensate my sneaking up on her enemies. Basically, she sucks at this. While yes she can sneak up on someone she thinks mostly in the short term, and often fails to take out her enemies in a silent manner. This has repeatedly led to her alerting everyone in the area of her location, and gotten herself into trouble many times.
She sucks at understanding social cues and is prone to insist that certain things happen without first regarding the opinions of those who are involved.
TL;DR: The one on the left is Errant Callithumpus, an impulsive adventurer, and the one one the right is Omega Fuse, her friend, and a shoe maker.