Bingo.
Basic default settings use the value @active_battle, and instance value that can be reused for multiple battlers as it performs one battler's actions first... then another... and another.
Cogwheel's RTAB and his CTB (a variation) uses the local value of battler which they copied from the Interpreter class. As it is a local value, each actual battler's actions can be performed while other battlers are performing their own.
So you have to account for the new 'battler' value as it must be called in every routine in the system. Oh, and there's more to mess with... not just merely replacing values.
But, I doubt I will be avble to convert 'ALL' the features for the Cogwheel system... most, but not all.