You only lose hydraulics from the associated hydraulic system. Port engine is HS1 and starboard engine is HS2. HS2 has your brakes, tailhook, IFR probe, landing gear, launch bar, NWS, and gun. Both systems also supply hydraulic power to the flight controls. If you lose the starboard engine you lose gun and launch bar. Everything else still works top some extent due to accumulator in the emergency circuit of HS2. If you lose the port engine you still have everything hydraulic.