There is a few options here. If you go to the canine nutrition thread, there is a sticky for foods appropriate for large and giant breed puppies. Read the first few pages of information for the pup, and then page 36ish or so has the most recent one. Any food on that list is formulated for growth-also known as puppy food or all life stages food. You can keep all the dogs on this. Feed the overweight/not so active dog for the desired weight, and the other two appropriately.
Alternatively you could feed a weight management food for the one, and the other two on the same one.
