Notice the NY Times big two page spread of quotes today. The Producers have wisely divided the quotes 50-50 toward the divas. The show is taking the SIDE SHOW approach of promoting them as a duo, which is fair and wise.
Though the material is in no way similar (don't beat me up, posters) ...I think the division of musical labor here is reminiscent of FOLLIES. Dorothy Collins (Elphaba position) had the more emotional, but "plainer," less flashy role, and Alexis Smith (except for "Could I Leave You?") the acerbic comedy and sophisticated glitz. Alexis got the reviews, got the Tony and all others, even though Dorothy had to carry the show musically. The roles really were equal, but, per the recent book on FOLLIES' development, as the show neared B'way -- and "Lucy and Jesse" was written -- Alexis got the lion's share of the attention. I remember it clearly -- we had no boards like this then, but there was constant discussion about how Dorothy was overlooked, just like Idina today.
"I'm a comedian, but in my spare time, things bother me." Garry Shandling