The FMGS doesn't generate any speeds, at least not on the Pegasus types. The pilot inserts them, derived from the book.
There are no one set of V speeds for SRS. Green Dot, F & S speeds will be generated by the FAC, but the take-off speeds are pilot inserted.
There can actually be a whole host of various V1/VR/V2 speeds, depending on FLEX/TOGA/"going to the left"/"shortening" etc. for one specific mass at take-off for one specific runway.
Airbus is speed optimised as oposed to Boeing which is runway optimised.