Hand stands are a body weight exercise and therefor dependent on the clients weight to muscle ratio. It also takes superior muscle recruitment and stabilization.
The Arnold press hits-
Triceps Brachii, Deltoid Lateral, Supraspinatus, Trapezius Middle, Trapezius Lower, Serratus Anterior Inferior Digitations, Triceps Long Head, Trapezius Upper and Levator Scapulae.
It does all this while providing someone a safe amount of weight depending on their strength.