I very briefly worked in a similar organization a decade ago, and it checks out with how I remember things. Though in that case half the mess were from mergers

I very briefly worked in a similar organization a decade ago, and it checks out with how I remember things. Though in that case half the mess were from mergers leaving the bank with multiple instances of similar yet incompatible IT systems. Another source was the wave of regulation and reporting requirements crashing onto finance after the subprime crisis.