Every duckling is different, but from my experience, nothing good comes from having solo ducklings. I bonded very well with my 3 Cayugas who were 3 days old when I brought them home. I also bonded very well with my two goslings and two buff ducklings.
That being said, they do always want to be with each other. When they are out, I always have the 3 cayugas, 2 goslings, or 2 buffs, and sometimes all 7 of them. They all follow me, eat from my hand, and snuggle on the couch. A single, imprinted duck needs constant companionship, rather then the few hours a day that most would like to spend time with their ducks.
 
I like to say that I more bonded with my ducks/geese, rather then imprinted. Imprinting sounds wonderful, until you have a very needy duck! I spend lots of time with my bunch, but when its time for them to go back in the brooder, they cry for a few minutes, then go back to hanging out. It was extremely important to me that they be bonded to me, but I had to make the effort to let them know that they are ducks. 
 
If you want them to live together in the future, would you be able to just handle them together? Meal worms and food processed veggies helped mine ALWAYS see me as a good thing. They all love to snuggle up on the couch (when they were smaller, now in the grass) but when I leave, their world doesn't end. We would love to see pictures! 
 
Welcome!!!