Sure, I was just going in the spirit of the comment. I have a few friends from degrees ranging from philosophy and music to physics who did a few months somewhere in the City and then were working relatively well paid corporate jobs ("relatively" because London just eats everything until you make enormous amounts of money). I'm sure they were useful in some degree to the legal departments they entered after "graduating" from that course...
For a start there isn't a single legal system in the UK - Scotland has a different process for qualifying than England does and NI and Wales might have different processes.
In Scotland to qualify as a lawyer if you already have a first degree in another subject requires 2 years to get an LLB and then another year to get a postgraduate diploma in legal practice (both full time) then 2 years training at a law firm.
From what I can see in England the equivalent of the 2 years LLB takes 1 year but you still have to get a postgraduate qualification and do the training.
The Law Society for England and Wales says 4 years to qualify as as solicitor if you have first degree.
https://www.lawsociety.org.uk/law-careers/becoming-a-solicit...
Qualifying as a barrister (or advocate here in Scotland) ironically may take less time - but that's exceptional.
NB My wife did the "conversion course" route here in Scotland and it took 5 year and she went on to be called to the bar as an Advocate.