Is it best to use Arnold’s (Jay Cutler’s, Dorian Yates’) routine?
Generally, no. Using the workout routine of a lifter that uses steroids isn’t always the wisest decision. Steroids users can train longer, and with more intensity than natural lifters. Steroids users recover faster, and can overcome bad routine design easier than non-users.
It is best to consult with natural lifters on what works best.