The tricky word there is average. If Tadej can absorb an extra 5 grams per liter, then you should give Tadej an extra five grams per liter. If Jonas can absorb 2 grams less per liter than the average then you should give him that serving.
These race results come down to mere seconds per hundred miles, for cyclists that are averaging 20 miles an hour. Any 1% difference is going into the training regimen.