Whether or not this is a good idea is moot: this is in the bowels of the bank and not the bleeding edge of commerce.
It’s not clear where an ML expert who isn’t already familiar with the data and the business fits in or adds value, or even what an expert really means in industry.
Agree with your point about domain knowledge being important.
But you've also succinctly described why a huge percentage of ML as practiced in industry under performs or flat out fails. To a first approximation the person who reads a few tutorials and plays with example data sets, then sets out to apply it to their own domain, has no real idea what they are doing - and it shows.
These terms are meaningless in both ML and finance.
Perhaps, vetted and peer-reviewed on the one hand, and person on the commute bus with a pop-topic book on the other.. there has to be some awareness of that spectrum. With no indication of that awareness here, it just does not bode well.
[0] https://news.efinancialcareers.com/uk-en/3002418/machine-lea...
I have several friends who are machine learning practitioners. Many are actively looking to get out. When you strip away the hype and BS the demand in London is very thin.
From my experience, a large part of the demand also needs to be driven by the AI and ML execs' ability to sell to the business.
Edited to add: this isn't a diss on them or this phenomenon in general -- it keeps me employed :)