subpanels,overcurrent protection

[zeek]

a 200a service is established at a garage.
now the house is being built on the premises
with a subpanel established there, fed from the
garage. 200a subpanel fed with 4/0. can the
feeder be fed by a second 200a breaker installed
at the main panel? or does it have to be 75%
of the established service? if so where is it
in the nec.