>>> Right now I can unlink and mix cars from other links in an hour or two. Articulated cars are far more difficult to do this with <<<
Obviously if the TA were to go with artics they would have to be designed for the system, which would mean units shorter than 60' and it might not take any longer to substitute units if specialized handling equipment were available in the yards. For it to happen, the TA would have to take the decision to eventually convert the whole fleet through attrition over 40 years. Given the need to work with politically approved budgets, and the likelihood that no savings would be realized until a good percentage of the fleet were converted, it is doubtful that it could ever happen.
Tom