Wiring a new shop advice
Unfortunately this has quite a number of defects in it already, including a panel in a clothes closet, a panel in a bathroom, and 2 feeders (service laterals, really) to the same structure.
As far as splitting the laterals below the meter, that is just a matter of splicing space, and you will be able to resolve that with an additional box or gutter below or on the opposite side of the pole from the meter.
Normally this type of splitting calls for a main breaker at the meter, and then supply breakers to each lateral feeder that is not rated for the ampacity of the main breaker.  (But still, dual feeders to the house would be problematic.)
Anyway, the upshot of all that is that you are already at 2/0.  If you spend a bit more to take it to 4/0, then that wire would be legal at 200A.