I was replying to your comment, not the other. But sure, get 4 RPis if you want. You could also be using containers on them, and not need to swap whole computer

I was replying to your comment, not the other. But sure, get 4 RPis if you want. You could also be using containers on them, and not need to swap whole computers. Or run each app in its own chroot jail. Or run VMs. There are many, many ways to accomplish this goal.