Does a husband need to love his wife more than anyone on earth? Even his children?
The question implies there is a set quantity of love that a person can give. It also assumes that love for, say children, is at odds with loving your wife.
The greatest commandment is loving God, the second is loving our fellow man (Mark 12:30-31). This isn't saying that we give God 80% of our love and men 20%. When we love God, we naturally love our fellow man. Because we love God, we follow His command (John 14:15), and a part of those commands is to love your fellow man. "By this we know that we love the children of God, when we love God and keep His commandments. For this is the love of God, that we keep His commandments. And His commandments are not burdensome" (I John 5:2-3).
Love for your wife is not at odds with loving your children. They mesh together in perfect harmony because over all of it is our love for God. When you show love for your fellow Christian, it doesn't mean you love your wife or children less. It all fits together because of our love for God. Your wife and your children are probably the easier people to love because their love is being returned to you, but it doesn't mean you can't love others at the same time.
"And may the Lord make you increase and abound in love to one another and to all, just as we do to you" (I Thessalonians 3:12).