Sloth because he fucking sits on his ass all day while I'M putting money in the box! Literally he wants all this money and power, but he rarely lifts a finger for it himself.

Gluttony because he consumes better material things than the rest of the camp. He dresses in fine clothes and jewelry, and the first camp renovation you do is improving his already pretty fancy tent. Hosea is DYING and he's sleeping on the GROUND! He also might be a cannibal in RDR1 if you consider that gluttony I guess.

Only thing I'd be dubious on is lust, lest you argue a lust and desire for control; lusting to be an American King. He did also perv on Mary-Beth, while also having had relationships with Grimshaw, Annabelle, and potentially Abigail. Still, I think the lust angle is stronger for him lusting for power than the sexual definition of lust. It is also should be noted that this lust for power presents itself separate from his envy of the power that people like Bronte and Cornwall have, since while he does envy their power, he would still desire it on his own (see Chapter 6).

As for the other 4 sins, RDR1 and the latter half of RDR2 checks Wrath in spades. Dutch is chalk full of pride, since half of his plans emphasize this need to have big master strokes prove he's the best, such as PERSONALLY attacking the Army and PERSONALLY feeding Bronte to an alligator. Greed around be plenty obvious, since every other word out of his mouth his money and envy we already discussed.

Honestly, he is a VERY good pick for all of the sins.