the electric pump on the blue system is powered after starting both engines.
Wrong
The blue pump runs automatically when either engine is started and ac power is avail.
With ac power avail, the blue pump runs automatically if the nose landing gear shock strut is extended. (Sensors GA24 or GA25).
Auto RAT extension requires airspeed and posssibly to be in the air. As when doing the auto Rat deployment test we have to switch the ADIRU #1 On and simulate an airspeed and in air mode.