It's not a particularly interesting question. It's almost the definition of a wrong question.
Most smaller church / religious outreach organizations that focus on poverty _within their local community_ end up being very efficient. But a soup kitchen is already a huge asterisk on the word common. You can't reliably feed humans with a global strategy: successful charity only happens locally.
This blog post looks like a reasonable assessment of the allocation of US$20,000 of capital in isolation. But it's clear that such a small amount of money can't possibly have an impact on the global population of humans, taken in isolation. By definition, any assessment of the common good depends on all common actions:
If you want to know what the common good is, it always depends on what everyone else does.