Hifly, hello. Briefly:
Airbus typically base T/O speeds on an Optimum V2/VS Ratio.
For 4 eng a/c there will be a
range of ratios. For 2 eng a/c there is only
one optimum ratio.
V2 is a factored value of VS which in itself is a function of weight.
Long runway, low weight high probability of unity for V1/R/2
Suggest read notes in FCOM2 (as was) or current Book 4 in the Perf/TO section.
Out of interest: Did you notice the speeds on the output from an automated T/O calculation program, or from inspection of a RTOW page. (I'm guessing the former
)
P.S. Just read yr profile. Sympatico on losing yr Cat. When I lost mine, felt like me legs 'ad gorn!