when it comes to the fraternity of banking, one can often disregard the supposed rivalry that is said to exist because incestuous relationships are commonplace

Beleive me, there's serious competition between banks. Just because it's carried out in a more-or-less civilized manner doesn't mean it isn't real.

But banking is an unusual industry, requiring a great deal of cooperation and coordination between competitors just to get business done. Perhaps some people mistake it for shady doings, but it isn't. If banks couldn't coordinate things closely with each other, you'd find life much less convenient.