I would like to ask you to consider something regarding protecting your husband. Perhaps it’s not a matter of the descriptor (as an adjective or definite article) relating to possession and possessor that should be considered; but rather the verb of Mark 12:31.
While this is a wonderful concept I would ask you to apply your logic consistently. If you are using this to describe your behavior and relationship towards your husband, then I must ask if you go to every neighbor you have and protect them from marrying a "wrong" woman as well. Do you go to every neighbor and help them with every detail of their life? If your husband has asked you to help him, then you may give him advice and your view. You are not his defender though. I am not Christ's defender for He does not need my help. If your husband is pursuing a relationship you are not ok with, you are not to oversee this process. He may ask you and that's great, but he may not and that's Yah's order that He has put in place.
To love is above all else. Love your neighbor. Love brothers and sisters in Christ. We must love our husbands. One beautiful example of love is Mark 14:47.
The Matthew rendering may help your understanding.
Matthew 26
51And lo, one of those with Jesus, having stretched forth the hand, drew his sword, and having struck the servant of the chief priest, he took off his ear.
52¶Then saith Jesus to him, 'Turn back thy sword to its place; for all who did take the sword, by the sword shall perish;
53dost thou think that I am not able now to call upon my Father, and He will place beside me more than twelve legions of messengers?
54how then may the Writings be fulfilled, that thus it behoveth to happen?'
Jesus rebukes Peter for his well meaning action. He basically said "Peter, I dont need your help, my head(my Father) has me taken care of. This is the same in your relationship. The Messiah will defend your husband. Peter's well meaning action stands contrary to the will of the Father and The Messiah.
After 21 years of marriage I certainly consider my love for my husband to be valuable enough to feel duty-bound to him, and that includes defending and protecting him.
You are very valuable to your husband. And once again, if he asks for your advice/help that is wonderful. However scripture does not define you as a defender of your husband, often times a well meaning defender can overstep their boundaries. For example Peter in the passage you quoted.
The noble wife of Proverbs, that so many wish to emulate, does her husband good and not harm (defends him from harm), watches over the affairs of her household (protects him in being responsible for the household that represents her husband’s affairs), and is praised by her husband for having done many noble things and fearing the Lord (those actions done because of love).
I agree that a noble wife does no harm, that does not mean protects from harm. If you husband is sent to war by Abba, you do not go before him to protect him, his head does, The Messiah. A well meaning woman will very easily, as the weaker vessel, bring emotions into an important decision. You are a great asset to your husband when you operate in your called position. Your husband needs no defense but from his head. I am glad to see that you have such a caring heart for your husband, but I caution you to understand what happened to Peter when he thought that The Messiah needed his help. Shalom.