I'm 57. Highly ambitious -so is my husband. We've both had successful careers and after 5 years in an insanely high paying career - very similar to your high paying industry - he switched to a lower paying field that is also very prestigious - but not lower paying in any dramatic way meaning if needed he can be the primary provider with no issues. I am thrilled he switched -he followed his passion and he's highly ambitious.
I switched after 15 years to a career as a full time mom -meaning - zero pay -and I was very ambitious at it in the 7 years I did it and never returned to the intense, competitive, crazy hours high paying career -I was 50 when I returned to my former career but in a part time capacity. My point is I'd look more at his values and his drive to determine ambition. It sounds like what you mean by ambition is a desire to advance in order to make the big $$$.
That is not him -not now and assume -not ever- I know of one couple where she told him -I'm not marrying a classroom teacher (this was in the 1960s) so he became a doctor despite his love of teaching. Made a lot of $$. For them it worked -they've been married oh 60 years or so - but I think it's rare that a person will change their whole career trajectory as an adult especially in order to conform to your notion of "ambition" meaning -mostly the salary.
He might -but he'll be miserable don't you think? Now is the time to decide your musts -and it's ok if others might find it "shallow" etc - my take on you is you like your high flying $$$$ career but at some point want to be able to be a full time mom with a husband who makes enough so even if you don't sock away $ now it's ok, I socked away $$ for 11 years while I was single (after I paid off my grad school loans) in case I married someone who couldn't be the sole provider - because I knew I wanted to be home much longer than maternity leave. So it wasn't needed but I enjoyed contributing to the household income from my nest egg and obviously it's good as a woman to have that nest egg just in case.
Those are my thoughts. IMHO!!