Basic Payroll Processing should be similar no matter what Country's Payroll is being calculated, but there will be some variations.
In retroactive payroll calculation, some WTs (such as Basic Pay and Taxes) will impact the RT and CRT of the recalculated Pay Period while the variations in Net Pay will be carried forward to the current PP, and some other WTs (such as Deductions) will have their variations carried forward to the current PP through the Arrears Table (ARRRS) since the Check/Bank Deposit amount can't be modified for the recalculated pay.
Try using table view V_512W_O to compare the Processing Class parameters of WT 9000 with those of a Basic Salary WT.