@JeanieBurrell A lot of schools of anarchism assume that the old world needs to be destroyed before the new one can emerge. I don't believe that's true at all, so yeah, I do expect that people will probably interface with capitalism.
So let me introduce you to this thing robber barons used to build the first monopolies: vertical integration. Rockefeller Steel needed coal to smelt, so they bought coal mines. They needed trains to move the coal, so they bought train lines. Sometimes they built new train lines. Oh hey, they already have steel to build the rails and they already have coal to power the trains. Suddenly they can out compete anyone because their whole supply chain is within their organization. From there, they could undercut everyone else's prices to drive them under and buy them out. That's how the first monopolies were built.
It's illegal now, for obviously good reasons. It's far too powerful to trust capitalism with. But a distributed system could share or trade goods internally for lower costs than they sell them externally. They could figure out internal supply chains to sell things externally, then distribute the profits back... or keep prices super low to sink capitalist competition. An organization like that could follow exactly the monopolists pattern of using market share in one domain to leverage into control of other markets, taking over the whole thing bit by bit. It would be extremely hard to stop since there isn't any law stopping a non-profit from being a monopoly and, even if they created one, they wouldn't have a centralized organization to go after.
Such an economic strategy would be really hard to counter.
But that would take a little bit to scale up to. Just starting small, yeah, I'd absolutely assume a lot of interaction with capitalism. The whole point would be to just reduce the burden a bit in one area so people in the collective do a bit better than people outside. That brings more people in, which lets you do more, which lets you take a bit more pressure off. People bring their skills when they join.
Now, after I got out of the hospital I had a couple of (unofficial) visits from nurses and other medical folks. I didn't have to pay for them. I didn't have to figure out insurance. They were anarchists. They were limited in what they could actually do, legally, but they volunteered a bit of time and their skill to help me because I put my life on the line to fight something we all opposed. That's just mutual aid.
So I don't think it's necessary to figure out how to bootstrap an entire medical system tomorrow. I don't think I could do that. I don't expect individuals could. But I already know anarchist medics who would be happy to work outside the system if they could have basic needs covered. Now how many people does it take to do that? That's a good question. The more people work together, the more mutual benefit. Being alone and poor is expensive. But if you work together you can afford to buy things in bulk, making stuff cheaper. You can rotate cooking so people have a bit extra time. People can take that extra time and socialize, recharge, or work on other projects to bring in a bit more cash. Cooperation compounds over time. Little bits of extra money saved by cooperating can go in to a susu (https://en.wikipedia.org/wiki/Susu_(informal_loan_club) or something similar, which lets people invest in things that make their lives even easier/cheaper/etc.
Now, I assure you, there are absolutely people who would be thrilled to trade their medical skills for a chance to exit the system. Since you bring up midwives, there was actually a commune that brought midwifery and home birth back to the US in the 60's. A lot of US midwives trace their influences back to that commune.
It's not only in the realm of possibility, that kind of thing has absolutely happened. It's really a matter of scale. The important difference between this proposal and the commune movement is that communes tried to be completely removed from capitalism while this continues to interface with it while working towards a full exit.