6 is about vigilance and endurance, Sp is about safety. Sp 6 seek safety, Sp-last 6 don't.
"Type 6: The committed, security-oriented type"
"Basic Desire: To find security and support."
(Taken from "The Wisdom of the Enneagram")
Notice the word "security".... "Security is the degree of protection against danger, damage, loss, and crime." "Safety is the state of being "safe" (from French sauf), the condition of being protected against physical, social, spiritual, financial, political, emotional, occupational, psychological, educational or other types or consequences of failure, damage, error, accidents, harm or any other event which could be considered non-desirable. Safety can also be defined to be the control of recognized hazards to achieve an acceptable level of risk. This can take the form of being protected from the event or from exposure to something that causes health or economical losses. It can include protection of people or of possessions."
Yes, generally, all sixes are security-oriented, and therefore, safety-oriented. I agree that possibly certain instinctual types and mbti types may be more "safety freaks' than others, but all sixes are generally security-oriented.
I, for example, would be the type to install $2,000 security windows, and install a camera system in my home. My mother, an istj 9 sp/sx, while she is more of a safety freak when it comes to certain activities (like sky-diving), would never go to the levels I would to keep her home free of intruders. My mother is a safety-idiot when it comes to protecting herself against other people, and she has even left me in dire circumstances when it comes to this. I think sixes have the security issue covered, in general, more than any one mbti type. Now it's possible that an istj 6 would be more of a safety freak than me, because they might have the "safety freak" concerning physical activity covered, whereas I am willing to take risks when it comes to certain activities, and risks in other areas of my life, and istj wouldn't. I know an estj 7w8 sp/so, and he's nowhere near the safety freak that I am. While sp seems to make a difference, I think when sixes have sp as their least developed variant, their safety orientation might manifest itself through the social and political, and/or other arenas, which is still considered "safety".
When it comes to the definition of "safety freak", there is generally a 6 involved lol; they seem to be more apt to go above-and-beyond the norm.... S.P. also means an orientation towards safety, but only of the physical variety.