Don’t understand how pitman and idler arm work at spec torque settings?

The tighter the bolt the better. Just don't strip it. If it is binding you have a stiff or incorrect arm. The arm itself should not bind on the K-member. The k-member ears should be toghtened firmly against the sleeve the it spins free on.. It this the style arm you are using. The washers , foam seals and sleeve do not move. Only the iron arm