I hope you won’t be disappointed in my obvious softness in allowing you to use the rolling method from Dragon #39 for your primary “Adventurer” character:
“Roll 4d6 seven times. Record the sum of the three highest six-sided dice. If that sum is six or less, reroll at once. The sums must be recorded in order. The player is allowed two chances to alter the numbers as recorded. She may switch the positions of two of the numbers and she may discard one number – not necessarily the lowest one.”
You may not combine this with the ACKS core raising of a prime requisite ability or abilities by sacrificing points in other abilities.
I very much like “organic” characters, and I especially do not like frequently occurring characters with an 18 in their prime requisite.
You can use the other rolls above for your entourage characters (similarly without raising/sacrificing).