I am from a medium sized family. Not sure what category you would assign it. I am the middle of 5 children. We were raised in a somewhat traditional fashion and although I had the normal childhood / teenaged growing up angst, all in all it was great.
I had some of the classic middle child syndrome views and experiences, but while I was living it, I didn't know anything about that and it was very real. I only read about it in my early twenties and it gave me pause. How on this earth can birth order cause similar feelings and perceptions?? No matter, I still lived it !
As an adult, I have always thought about how lucky I was to be born into the family that I was. We are very lucky, because among us there are no advantage takers and like your family, we always know that if times go wrong, the others are there for us.
I've always pictured it as a safety net of sorts, in that it gave me courage to go out and do things, knowing I could never fall quite all the way down.
Growing up I thought most everyone was nearly like us, but I didn't get very old before I started becoming aware and hearing the stories and found that we might be more of the exception instead of the rule.
God.... and my family..... my two most important things. :)