He’s ruthless, of course. Incredibly smart. (“Is that scheming face?”) Iron-willed. That he can dominate even with his damaged leg suggests he isn’t a Body Type. His dexterity suggests he is. Are his lockpicking skills inherent, or a product of his determination?
Loyal. Patient. He doesn’t need instant gratification: his revenge plans go on for years.
He’s a Five. It’s his observational skills. He can find the best crew, and he can concoct the most efficient plans, because his brain is always processing data. Inej surprises him when she approaches him at the Menagerie. He didn’t know she was there, and he’s super impressed by that. Immediately he arranges to buy out her contract and offers her a job. After that she never surprises him again. He heightens his ability to observe her. He knows everyone’s tell, and realizes the moment he’s shown one of his own. It’s that uber-consciousness that identifies him.
Also, he loves his crew but he never shows it or even thinks in those terms. His loyalty and his planning are how he proves himself. If he didn’t care, he wouldn’t do those things. This is very Head Type.