
I weaned my last Chi litter on the Fish4Dogs small bite puppy. I did, however, give nature diet puppy all the way through. I've never had tummy upsets on it either.
At 6 weeks I like mine to be a little on the chubby side, I always believe it gives them something to fall back on if they're not well.
At 6 weeks mine were given the meat 5 times a day, and the dry food was left for them to take ad lib.
I don't see that you have anything to lose by giving it a go. Your pups will be a whole lot bigger than mine. :-)