Although Star of India's rating of 138 is not a true reflection of her ability, there is a reason why these apparently bizarre 2-y-o ratings have been arrived at.
Most people seem to overlook this, but Timeform annual ratings were never intended to reflect the "true ability" of horses, in the sense of being intended to be able to be used to compare top performers from different eras.
This is what Randall and Morris have tried to do, which is why they've altered the ratings to reflect their opinions regarding the relative abilities of top horses over the last century.
Timeform, ie Phil Bull, used to work on the basis that each generation, as a whole, was of equal merit to any other generation, a somewhat dubious assumption but there it is. But if you start from that premis, then it's only to be expected that you'll get some exaggerated ratings from time to time.
Furthermore, these are especially likely to be concentrated in the 2-y-o division. This is because the spread of ability, due to the greater relative variations in maturity of 2-y-os as compared to 3-y-os and older horses, will be wider (both at the top and bottom ends of the ability range).