You missed one key consideration. It could also redirect money from more efficient overseas charities to less efficient US charities and even if this was a small amount, it may still be net negative if the utility difference was large enough.
I believe this is number 2 under “Costs (if successful).”
I believe this is number 2 under “Costs (if successful).”
You’re right. Edited my comment to note that this was actually addressed.