That is impossible because each Vanguard mutual fund is a distinct legal entity. Assets cannot be moved between funds. See Vanguard safety for more details: https://www.bogleheads.org/wiki/Vanguard_safety
Vanguard has about 30 SEC registrants (formally, Delaware Statutory Trusts) for all its US mutual funds. But it has a lot more than 30 funds. For example, VMFXX is managed by Vanguard Money Market Reserves, which also holds VUSXX and the former VMMXX.
