Recommendation on training strategy

The answer would depend on a lot of factors you haven't discussed--number of employees that need the training, complexity of the issue, time zones involved, how fast this needs to be done, and more. If the audience is large and geographically diverse, training everyone in a classroom (even virtual) might not be practical. Often, providing a blended approach as you described can be very successful, with self-paced learning for many of the details and even practice sessions, mixed with a live training led by experts, to let learners get hands-on time and questions answered. Then follow that up with supporting materials--step-by-step videos or job aids, manager follow up, etc. That kind of approach can prepare your folks and reinforce the new tools, processes, etc. Hope that helps.