You describe a united Tower with a strong Amyrlin, which isn't really a worst-case scenario. A thorough bashing of the rebels wouldn't improve things nearly this well-- Elaida is still an incompetent Amyrlin, the Ajahs are still split, and the Black Ajah still infests the Tower.

Egwene sees the clarity of this in TGS chapter 16, when she says: "I would willingly accept execution, if it would mean leaving a competent Amyrlin."





By focusing on a connection from the Tower, to Rand's entourage, and then to Rand, you've set up a straw man.

Rand needs Moirraine (known from Min's viewing). Moirraine needs to be rescued from the Tower of Ghenjei. But the Dark One hasn't exerted any power to affect, nor sent minions to guard, the aforementioned Tower of Ghenjei.
Ergo, the Dark One is irrelevant to Rand.

Straw man.


But to answer your question more thoroughly, I'll break it into two parts: First, I'll list differences between Egwene + united Tower (what we got from the struggle) and the fractured state of rebellion with Elaida holding Tar Valon (what we had). Second, I'll show why the White Tower might be useful.


DIFFERENCES

* Elaida made incompetent decisions:
Such as the proclamation banning contact with the Dragon, the Cairhein kidnappers embassy, and the Black Tower expedition. She is in denail of reality, such as the threat of the Seanchan. That's all water under the bridge, true, but past peformance *is* a strong indication of future results.

* The Ajahs were fractured and combative:
Elaida was in denial (again) and Egwene has already made huge strides to fix this.

* Egwene cleared out much of the Black Ajah:
You could argue that it was only because Verin and the gang of Rod-wielding Sitters trusted Egwene, but when we're talking about an Amyrlin, that's the point. Verin didn't trust Elaida. Elaida's own group of huntresses were set to find rebel spies, not Darkfriends, and they didn't trust Elaida enough to report their findings. Had they asked Elaida to re-take the Oaths under their witness, she would have likely refused (denial!).

* The Aes Sedai are able to bond Asha'man:
Remember that Rand's proclamation applied only to those loyal to Egwene. They were unlikely to do the bonding while busy rebelling (and would have still been disconnected from the Tower and any central guidance if they had). Elaida never would've accepted that Saidin was cleansed (denial, again!).

* The thousand or so new novices, many overage, can be tied to the Tower:
That's Egwene's doing. Elaida would not have accepted them.

* The Kin can be tied to the White Tower:
That's another two thousand channelers, also unacceptable to Elaida.

Note that these two groups are impressed by the White Tower mystique, and therefore *much* easier to command and unify when the Aes Sedai themselves are unified. With Elaida in charge, they would be spread out and disconnected, their talents useless at best, or collared by the Seanchan at worst.

* The nearly one-third of Aes Sedai who are "sideliners" now have someone to obey & follow.
(Again, recall Elaida's poor leadership when considering what they would have done had Elaida cowed the rebels.)

* Cooperation is possible with the Aiel Wise Ones & Sea Folk Windfinders
Conventional pre-Egwene thinking considered them to be inferior Wilders, and/or that they shouldn't be *allowed* to channel, let alone taught anything that might be of use (in the last battle, for instance)

* Cooperation is possible with the Children of the Light (Galad), the Younglings (Gawyn), and the Throne of Andor (Elayne)
Perhaps the Younglings followed Elaida, but they weren't being put to very good use, were they? And Elaida was *still* planning to snatch Elayne and drag her back to the Tower. Big disaster, there.

* The Aes Sedai army is over *twice as large*
Gareth Bryne wouldn't have followed Elaida. And thanks to Egwene's peaceful resolution, the armies are largely intact.


There were somewhat less than a thousand Aes Sedai, split into 1/3 rebels, 1/3 loyalists, and 1/3 sideliners. Roughly 20% of these were Black Ajah.

So I estimate that Egwene now commands 500 Aes Sedai currently in the tower and another 250 sideliners.
Elaida would have had closer to 400 tower Aes Sedai (after accounting for her purge of the rebels, dissatisfied deserters, and greater losses to the Seanchan raid). Giving her all 250 sideliners (doubtful, but I'll be generous) is a total of 650 *minus* 200 Black Ajah (they're working against them) for an effective total of 450 Aes Sedai.

Grand totals,
Egwene: 750 Aes Sedai, 1100 Novices & Accepted, (up to) 2000 Kin, 53 Asha'man, x soldiers
Elaida: 450 Aes Sedai, 100 Novices & Accepted, 0 Kin, 0 Asha'man, 0.4x soldiers


FUNCTIONS and RESOURCES of the TOWER

* Fight at the Last Battle
Really, that's enough right there. With Egwene, their numbers and leadership are vastly superior.

* Assault the Black Tower (probably in cooperation with Rand)
We all know it has to happen, with bad guy Taim running things. See above re: leadership and numbers.

* Resist the Seanchan
You could argue that we'd be just fine letting them all get collared and fighting that way, but Rand (who needs to bind the Nine Moons, and visa versa) is violently opposed to collaring. That goes double for the ladies in his entourage.

* Teach
Even if the Seanchan could capture all of the Wise Ones, Windfinders, Kin, and older Novices, they wouldn't have enough Sul'dam to train them all; they would be short on time, because their process requires breaking before building; and they wouldn't teach many things (Healing, warding, linking) that the Aes Sedai do.

* Bond more Warders
Damane, Wise Ones, and Windfinders don't do this. They would never learn if Elaida had her way (nor would the Kin be allowed, of course).

* Guard their stash of Angreal, Ter'angreal, and the Horn of Valere
All in the custody of the White Tower, and all in danger of missing the Last Battle given the Black Ajahs infiltration and Elaida's capacity for denial.

* Stabilize nations
Rand + the Seanchan don't control everything yet. Uncertain nations include Arad Doman, Murandy, Saldea, Kandor, Arafel, and Shienar. The Aes Sedai have always had a strong influence with the Borderlanders in particular; their armies are curiosly absent from the Borderlands at the moment; and said armies are curiosly accompanied by a number of Aes Sedai.

* Whatever comes up
Barely half a dozen people are actually *required* (by Prophecy) to do something useful between now and the end (Rand, Mat, Perrin, Cadsuane, Alivia, Tuon). For everyone else-- including the Seanchan, the rest of Rand's entourage, the Asha'man, and the multitude of armies-- their usefulness can only be speculated based on their resources and temperament.

The White Tower still is still a vast source of knowledge and diplomatic reputation. Egwene commands more channeling power than Rand, the Aiel, or the Sea Folk, and at least as much as Taim or the Seanchan (at least on this continent). Furthermore, the Aes Sedai outstrip all of them in skill and experience; and, in case you hadn't noticed, Taim and the Seanchan are still Rand's enemies.

-J