I agree with that advice.
We had 2 toy poodles, ( 9 lbs male and 6 lbs female), when we brought home our first boxer puppy ( 12 lbs at 8 weeks old ).
My boxer, Daisy, let both poodles dominate until she was about 18 months old... when we saw Daisy begin to challenge the much smaller dogs we helped the transition along by feeding Daisy first, letting her in and out first etc... the poodles learned very quickly that Daisy is now the dominant dog. If we let Daisy continue to challenge the poodle's authority it may have lead to a vet bill or worse.
The poodles and the boxer get along very well, enthusiastically greeting each other after being seperated. When they are playing, ( and they play alot), the boxer will still roll over and let the poodles jump all over her.
I hope it works out well for you.
randy and Daisy