Plagueis was stronger then pre-prime Sidious. Sidious became stronger since TPM.
As I remember, Lucas was asked why B-team members died so easily, and quote about Yoda and Mace was actually a part of his answer to that question. Which may mean, that Lucas was talking about sword fight, not all-out. And lightning part is that one, when Sidious fakes his weaknes.
Windu should takes sabers.
Plagueis takes the Force and should take all-out as well.