Another thing to consider is that these are near constant-power engines over 33% of their rpm range. This means that gearbox ratios do not have to be very close to achieve best acceleration. For example a constant spacing of 1.2 (20% rpm drop) throughout the box would allow shifting at 11,700 and only dropping to 9,750 in the next gear. The 1.2 spacing would also mean top speeds (at 15,000 rpm) in the gears of 119, 142, 171, 205, 246, 295, 354, 425 kph, the point being that 119 in first gear is pretty low by F1 standards so no problem getting off the line.
It is most probable that 1st gear would be somewhat taller - and - the ratio spread would reduce as you go up in gears eg 133, 172, 215, 262, 309, 354, 394, 425 - giving a finer range of top speeds for different tracks.