I guess it is something I picked up old school, out in the field, pre-internet. I never met a dog, one or two syllables, I didn't like. Trainers and owners.....well you certainly understand.
Found this for an explanation:
Two syllable naming a dog.From above link:
• Your dog’s name should be two syllables – Research has shown that two syllable dog names are the best for your dog’s learning. Names like “Spike” – one syllable names – sound more like commands than names. Notice that all commands are designed with a single syllable (“Sit,” “Stay,” “Down,”). That is because single syllables resemble barking – the way that dogs give commands in the wild. Your dog’s name is not a command, therefore a two syllable name is far more effective for dog training.