Legendary armor is too good. The other two options are generally far too weak.
Yes, Space Marines and CSM have relics which give +1 Save as well as an extra additional buff, but Space Marine characters generally A, already have access to a 2+ save at the cost of mobility options or B, aren't hard to kill regardless of their armor.
Giving a 6w T5 character (like a SM Biker) a 2+ save is strong. Giving a 14w, T8 character (a Tervigon) a 2+ save is broken.
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