If it were for a second primary weapon on your strong side, I would go with the Matriarch. Reason being its primary purpose would be to slash and cut with minimum training as Spyderco puts it using basic movements.
For a back up, I would say go for the waved Endura. The wave will allow it to open in deployment and allow you the options of slashing, cutting and stabbing.
Say if you are held from behind, you will not be able to stab with a Matriarch and like another forumite said, Matriarch tip is not meant for stabbing.
Just my thoughts.
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