It plays to his strengths. And might strip a layer or two off Winterfell's wards.
"Ser Richard, what purpose do you serve at this meeting?"
Ned: "That's not--"
Richard: "Lord Stark, I'm your baseline."
Viserys: "He means control case in our study."
Richard: "Right. Basically, I am the most loyal man in service to His Grace."
Richard: "If I think something is suspicious, it very quickly stops."
Ned: "Stops being suspicious?"
Richard: "Either because it stops moving or doing anything useful while I'm around, or because it
stops."
Viserys: "I also have a four year old on-hand to tell me any obvious faults or flaws in my plans, and a token evil minion who strains the edgemost limits of their oaths nearby at all times."
Ned: "...
why?"
Viserys, pointing out
very quite reasonably: "Well, I don't have assassins crawling through my Keeps constantly, or traitors advising me. Probably because I have people who can spot treachery, stupidity and someone to act as a test-bed for stupidity and treachery."
Ned, to Richard: "And you serve this man?"
Richard: "He's not been particularly wrong by my own exacting standards."
Ned: "His father murdered my family! And his brother started it all!"
Richard: "Yes, and they're dead, and the fruits of all your collective fuckery is in evidence today."
Viserys: "It's hard to argue with that..."
Ned: ☹