This "vicious" idea of intruducing lovebirds to one another is stupid. If you pair up two birds who do not know one another in a cage, of course they are going to disagree and fight. The prior resident bird is going to defend his food and territory and the newbie has no choice except to fight to survive. Moral of the story? Do not put a stranger bird into another bird's cage. However, if you want a flock of two or more of the same species, when you obtain the new bird, also obtain a cage just for the new bird. Set the two birds side by side. Let them get to know one another through the bars. Then let them out at the same time and give them opportunites to interact. Within 30 to 60 days they will either bond or just decide to be friends from afar. For me, this has never failed. And I have built small flocks of lovebirds, budgies, cockatiels, canaries and doves with this technique.In my experience, it mimics the way wild birds join wild flocks.
As far as finding a bonded mate for a bird, I have had NO luck with Sunshine Senegal. I have looked and looked, taken an option on cock Senegals four times and Sunny has eventually attacked and rejected every one of the cocks. I have finally accepted she does not want a bird mate; she wants me and only me. Sunny was an incubator raised chick, 100% human hand fed and never interacted with another bird until she was two months old and able to join a multi-species creche. My conculsion is that Sunny is human "imprinted" and not at all interested in living a bird life with a mate and a flock.
Gracie, my first cockatiel, despite being an incubator bird and 100% hand fed, accepted the first cock I brought home to her. I gave him is own cage until he and Grace began to shack up together and then they surprised the heck out of me by giving me grand-birds. Not all incubator birds are exclusively into humans. Sunny just happens to be one. Gracie was not. Use the separate cage introduction method with whatever opposite gender bird you buy and wait for the hormones to flow during mating season. I have found the hormones make it easier to bond the hen and cock, as the mating imperative makes them decide to use "the one your with".
Hope some of this info helps.