I believe intelligence in dogs can be measured many different ways. All of the expert reports on dog intelligence that I have read focus on tricks and obedience tasks. I believe they should look at more.
My boys do not know a lot of tricks because I am a terrible trick trainer. They are really good at learning life stuff though. They know way too many words, spelling, and so on. They excel in picking up life routines.
Funny story about tricks though -- Teddy took a year to finally shake hands with me. He would watch Max do it, but when it was his turn, he would look at me like, "This is dumb. Why do you want me to do this?"
I would say both of my boys are strong willed, definitely not submissive, but generally eager to please.