The government can appropriate the funds it needs to ensure the welfare of orphans.
A charity must necessarily brand its orphan welfare services and thenceforth be at the mercy of the vicissitudes of the market.
Whether competition will result in better orphan welfare services is not immediately knowable. What's important is that it is a transparent operation, involving checks and balances, that ensures a modicum of accountability in its delivery. This will deliver better outcomes for orphans. Such operating conditions could exist in free-market or state-run welfare services (or both). But it's not hard to see that an orphan welfare service that can appropriate funds has its advantages, though this is a pissweak argument for the existence of the state.