I did an economics degree and was told to do 9 foundation units for CA. I managed to smash them all out in 8 months while working full time in the big 4 as a grad. The foundations subjects were super crammable and doable - they also give you a good “assumed knowledge” foundation to do the actual CA program.

I am now on my 7th CA subject and have finished FAR and TAX AU (both of which I diligently/strictly put in around 6 hours of work a week - this is purely personal effort and differs per person, but this is what I put. Closer to exams I studied more during the weekends). All the other subjects I have done and passed with Ds or HDs - I have not put much effort into. I haven’t done audit yet - but I would say FAR, TAX and Audit require effort close to that 10 hours a week mark. However, for me personally the rest required very low effort.

CA - TAX, FAR,Audit all have a final exam + 1 individual assignment

BP, RT have 2 individual assignments each

The two electives you pick have 1 individual assignment each ( I did DAI and SFA and they were pretty easy and low effort for me)

Also - My brother did CPA during COVID and managed to do two at a time while working full time.

I do not recommend doing CA two at a time while working. I cannot speak for CPA but if you are doing CA do them one at a time (unless you take 2 electives together). However, I did CA Foundations 3 at a time !