Actually Egwene does not want Aes Sedai figthing Aes Sedai or to take the Tower by force. Why else would she have settled down for a seige when she could just as easily have Traveled with the army and rebels into the WT itself when the Aes Sedai there were not expecting them. 300 Aes Sedai plus 30,000 heavily armed soldiers at key locations say Elaida's study, the Hall to name but a few and the war is over very quickly. Egwene realised that this would cause bloodshed and even if her side won the Tower Aes Sedai would not just sit back and take it, a lot of them would probably flee the Tower and then its back to square one.