He's going to drive Crow nuts too xD
Crow is super meticulous about thievery, but Hartley is just like "Hey, here's some money. It's mine now." He doesn't plan at all, which is like a cardinal sin to Crow. I could honestly see him trying to take Hartley under his wing and teach him how to steal more successfully

Also, I was thinking it could be funny if Hartley has a shameless crush on Penelope. He's younger than her and a criminal, so it would be interesting to see how all the others react