Ishamael is very clearly happy with the result; you can see him smile as he's disintegrated by Rand's banishment. The entire point was to get Rand either to fall to the Dark (which nearly worked, in one of the genuinely more implausible points of the story) or have Rand "defeat" him and break the cuendillar seal. It was a win-win scenario.
Even if this is what they're going for, how was Rand able to break the seal by using merely the Power? What even were the stakes in the confrontation that it was so important for Rand and only Rand to come? Why would companions die? Is the show really going to make an issue that their beloved heroines, Moiraine & Siuan, royally screwed up by taking the Dragon to the Eye?
The show has done nothing to lay the groundwork for this to be understandable. While we don't understand every last thing about the Eye ITB, we get who they confronted and what the fight was about and how and why Rand won, and what was gained, and they didn't need to make anyone look selfish or incompetent to do it
Moiraine could have kidnapped Logain to do the deed. From what we've seen it only required a man channeling into that "sa'angreal" to vanquish Ishamael. There's no evidence that the DR was required for that scene.
Fan of Lanfear