Puppies and kittens are 9 weeks old, dogs are much bigger though and try to play rough by going on top of them. I am always monitoring. Should I intervene scold puppies or let the kitten learn to defend itself? I am worried they can hurt kitties and would seperate them however, was told this is the best age to make them get along. Any experience or advice is appreciated!
You are the Alpha, the pack leader and it is your job to prevent injury to members of the pack including kittens. If you feel the play has gotten to rough then step in and stop the play. That will not prevent them becoming fellow pack members since you are allowing them to interact under supervision. It just means that you are calling for a break or temporary end to the play.
But, also remember that young animals do often tend to play rough so just use your good judgement as to when it’s time to call for a break. One sign would be the kittens trying to get away or arching and hissing at the pups. Another would be when you, the Alpha, thinks the play is getting too rough and you need a break.