Congratulations! Your sure going to have your hands full for the next year, but what a happy one it will be....training, bonding and the like.
The only advice I can offer in getting the three introduced is to take the two new ones with you when you pick up Chuchi and let them greet one another on a turf that isn't theirs. Then take them on a long walk, and maybe even a dog park if the babies have all their shots. Get them use to walking around as a little pack before heading home. Make things fun for all three. Even if Chuchi isn't all that thrilled to the two new members of the family, he soon will. Yorkies are about the most resilient breeds I know.
Keep us up on progress.