A quick doodle I made earlier today, also the last pic with these two that I drew(but don't worry there'll be others, just not now, later). So a little reference from I got from looking at some doodles the owner of Crow drew of.
So due to Manehatten not being the safest place in Equestria at the current moment in time. So Quill tends to meet muggers and theifs whenever he walks back home, which he easily ends the event before it even starts by using his magic. Crow on the other hoof only fights when only in deep situations, such as a very difficult foe(like a boss fight) or when dealing with a certain amount of enemies(close to a small army or less), in which Crow will become psychotic and gain increase stats from agility to strength to etc. Quill learns that when Crow gets into this specific state, Crow will somehow create a long gap in her/his cheeks which shows all of the teeth to create some sort of grin-ish smile, but is not as disturbed as a regular pony because he knows Quill will only attack the enemy and not the bystanders/victims/etc.

Reference of Crow's "smile"(gaps may vary) → https://www.deviantart.com/pinkamenacheshirepie/art/Pony-Drawings-568395703
Clockwork Crow ©
Quill/Art © (me)
Mlp Fim © Hasbro and