All the same parents. My eldest brother is 14 years older. We have become much closer over the years as we have both moved into 'adult'. My other brother is 12 years older and I remember him more growing up as he was around more (Eldest moved out for uni at 18). We have always been close.
My youngest siblings was born19 months after me, so like a 2 seperate sibling groups in some ways, such as shared experiences, but we are all close. It is just the way our family is. Apparently my older siblings doted on me when I was a baby. Lots of my friends growing up had much younger siblings with a similar age gap so a similar dynamic I guess but they were the eldest.
It is not uncommon and I now work with children and families and it is not unusual. Families come in many shapes and sizes and in my experience, age gaps between siblings has not been a source of conflict or difficulty. There may well be other factors but not the age gap itself.