2/0 copper is probably an accceptable size for 200A service conductors in any case. However, even if it wasn't, the service conductors only needed to be rated for 150A (assuming that is the correct number for the PV output according to 690.8).
Article 230 simply requires service conductors to be protected by OCPDs that are rated no higher than the conductor. The fuses are the OCPDs, not the disco. There is no prohibition on using a disconnect that is rated higher than the fuses. After all, that's pretty much how a fused disconnect works; the disco can be rated higher than the fuses but not lower.
The code is a little lacking in that Article 220 doesn't specify how PV is supposed to be accounted for as a 'load', but the reasonable interpretation is 125% of the inverters' rated output as set down in 690.8