Hello!
I own two cats they are both 1 year old at least around that age.One has a thick, long fur but he's pretty small, by small i mean like a 4 month old kitten. The other one has thick, short fur and he's pretty big both his head, and body.
Why is this? They both get the same food rations, same care, born on the same day, same breeder and yet still.
Also both of them are half persian but the long furred one resembles a persian more than the bigger one, but persians are supposed to be big, not small.
Well, are you the same size as all the people in your class? There are probably some really tall, big kids and some really petite kids, even though you are all about the same age.
Same with cats. Some are big, some are small. It's just natural.
Persians LOOK big cause of the fur - in reality they are medium size cats - about 8-11 lbs.
And keep in mind that if the parents are not purebred and of the same breed, you have a lot of different genetics involved. Domestic long or short hairs can have lots of variations within the same litter and same parents if the parents are mixed breeds too .
Just like human siblings there can be difference between members of a family. One may be small and dainty, the other large and muscular. If this cat has not had a good physical examination that might be a good idea. If he is healthy, then he is just genetically programmed to be smaller and have a different coat than his brother.
Same reason why maybe siblings the same sex are different sizes. They just got different genes which made one bigger than the other. Maybe the smaller one is the runt.
