I had the intention of getting my second chin as a companion for my first seeing that chins can live for ten or more years. So is it true that chins do not need companions and are relatively independent creatures?
It depends on the chinchilla. I thought when I had to separate mine from his first roommate that he would want to have another friend/friends down the line. Turns out the bickering he was getting into with the other chin was mostly his fault, or he'd adjusted better to only chinhood than I thought, because when I tried to introduce him to a bonded pair, it went well for a while, and then he started bloody fights.
So he's a singleton on the lower half of a FN cage, while the bonded pair occasionally squabble over the water bottle or fleece tube, but never get too upset.
There's no hard and fast rule that "All chins like X"; some like human companions, like my two standards, some prefer chin friends like my beige. Some like women, like my youngest standard, some prefer men, like the beige again. Some like saucer wheels, some like vertical ones. They're as individual in tastes and wants as a dog can be.
The important part of keeping is, as was said above, how many can you keep healthy and happy? Were I to start over completely, I would contact a couple of the awesome breeder/rescues I know and ask for another bonded pair, males only since I don't want to be peed on from 6' away. No worry about "What if they fight?" while I'm at work, no months (Yes, literally months) of rearranging furniture to get cages in closer proximity until it's okay to try putting two 'stranger' chins together. Less chance of shock and panic when you come home to blood on a shelf anyway. The pair of adult males I keep now have been the *easiest* pets I have, and I have a lot of pets, so that's such a blessing.