Have you looked into what paid adoption leave you'd be entitled to? Check at gov.uk for the latest legislation, because it has changed to bring it into line with maternity entitlements.
SWs will usually want one parent to be the (initial) primary caring parent, during the transition and building of relationships - that's why they recommend one parent takes the long period of leave, rather than too much change of arrangements to start with. I can see that you're maybe going to be able to set up consistent routines of splitting the leave - it's likely to be about how solid the SW thinks that plan would be.
I should also say that there is a good chance your adopted child will have disrupted sleep, so trying to work after a broken night and then a day of caring for highly distressed children, can be exhausting beyond belief weary experience
I adopted one child with "no significant concerns" and it was 18 months before DD could cope with me working very part-time, and I am still not back up to previous work level (of 0.8 wte) another year after that. The impact of another move to me, on top of other needs that came out, makes it really tough for DD to handle separation. Some will handle that better, and some worse - ours is just one story. When it became clear a return to work was impossible and the 12m leave had ended, the LA did stump up for a year's adoption allowance. That kept us skint-but-afloat during the second year, but things were very tight.
My meandering point is, it's not that SWs want people who are wealthy, but the SWs know from experience many children cannot cope with one or both parents returning to work / being inconsistently available, until the child has settled more into placement - and that deeper settling can sometimes take years, not months.
These are all things you'll explore with your SW as you go through the process, so you don't need all the answers now, but it's good you're thinking about it. I hope it all goes well for you 