As above these are really distinct things. While I see how you've gotten to this point of reasoning, I think it is fundamentally faulty, as detailed below.
Firstly, I'd point out that whether or not you're a surgeon is irrelevant in your proposed route, as all NHS doctors are paid the same barring on-call commitments. In fact since surgical specialties take longer to complete, you wouldn't be a consultant for longer and would be earning less for a longer period as a resident doctor as a result. While surgeons can earn more with private practice once they become a consultant this is a) only after they become a consultant (so 16+ years away) and b) doesn't just happen automatically and I gather is something that takes some time to develop as a career to begin making a lot of money. There are also other specialties with similar scope for private practice work I gather.
Secondly, becoming a doctor is a pretty long and by all accounts demanding path. You really need to want to do it for reasons other than getting money to ultimately go and do something else. Also, relative to other careers requiring similar levels of achievement to start off with, medicine pays well but not extraordinary amounts. Doctors live comfortable middle class lives in the UK, they aren't rolling around in McMansion money to go off and start their own businesses after "putting in their time". It's not investment banking/tech startup money (although equally, comes with relatively less risk as once you get onto the degree, you're pretty much on the conveyor belt, whereas finance and tech sectors have lots of attrition and failure points).
Thirdly, setting up your own studio and creating your own original media is not just a function of capital. Even if you did have mountains of money you were sitting on, you can't just throw it onto something and call it a business. You need to actually have the skills and abilities to do the work, the experience of working on other people's IPs to understand what does (and doesn't) work in the market, and understanding the whole business of animation - not just the technical and creative skills, but also the production and business side of things. You need more than artists, voice artists, and sound designers - you also need a marketing team, sales people to get you onto major platforms/channels/networks, finance folks to oversee all the money of it, etc, etc.
Successful animators who create their own studios don't do so straight out of animation school, they do it as as the product of a long term career where they've learned (the hard way, sometimes) how to get to that point (and also if they have overarching direction of the studio - how to step back and let the individual creatives and teams work on things that they've delegated to them as creative director). For example, Hayao Miyazaki does not animate every frame of Studio Ghibli films, nor does he (at least by himself) do all the marketing planning and advertising and sales work!
"Paying ones dues" is not (purely) just a case of creative skills being taken advantage of until the person gets to step into the limelight - there is a significant component of, as well as doing purely scut work, doing smaller pieces of work in different areas in the sector to understand the big picture so that you have the knowledge to succeed when taking on the bigger roles later in your career. This is arguably not even really that specific to a creative career but probably applies to many/any career.
So I don't think your plan really makes sense, because you wouldn't actually in all likelihood spend 25 years as a doctor saving up tons of money (even supposing you are able to do that) to be able to just suddenly step out at the end into an equivalent level position as a creative director of an animation studio. You'd be going back to working on the bottom rung, having to do all the training from scratch (doing the animation degree, or equivalent preparation), networking from the ground up, establishing your bona fides etc.
Hence, if your ultimate goal is to pursue the creative career, it makes more sense to start that process now rather than begin a career in another area (which you may or may not succeed in) to try and later jump ship into a wholly different area.