Detailed:
Enlisted/Clan: ((Rank TP-3)/6 + 1) x base pay
Officer: ((Rank TP-3)/3 +1) x 1.2 x base pay
As far as adding the multipliers, that certainly is the AToW procedure, but not how CO reads on pages 24-25. Looking at the first example, which ends on page 27, it also strikes me the "Officer" multiplier was intended to be used in lieu of rank (i.e., your troops are either Enlisted and get base pay, or Officer and get 1.2 x base pay, leaving gradations solely in the hands of the experience modifier). The experience modifier appears to be straight multiplied, not added. If it were added, an officer of Regular experience would have a final multiplier of 2.2, not 1.2. It's the rank 0 problem again. By the AToW formula, the only people that get "Base Salary" are those with Rank 0. Even Rank 1 will be getting 1.33 or 1.16 of Base Salary.
Got bored, and ran some numbers in a spreadsheet, using the Detailed calculations to get the multiplier:
TP | Enlisted | Officer |
3 | 1 | 1.2 |
4 | 1.167 | 1.6 |
5 | 1.333 | 2 |
6 | 1.5 | 2.4 |
7 | 1.667 | 2.8 |
8 | 1.833 | 3.2 |
9 | 2 | 3.6 |
10 | 2.167 | 4 |
+1 | +(1/6) | +(0.4) |
Not sure if it will help, but sometimes seeing the actual numbers can make a difference. Off-hand, the increase in officer pay is 2.4 times as great as the increase in Enlisted pay, for the same +1 increase in TP