To use a corporate world analogy, all three are high powered execs you cultivate in your network. But Elayne and Nynaeve are the ones you hang out with at happy hour after work or on weekends, while Egwene is the one who absolutely will require a quid pro quo that will probably exceed whatever she did for you.
Actually, Egwene would hang at happy hour too, that was the point I was making. In fact, she's MORE likely to hang out there then they are, because Nynaeve and Elayne have opinions about debauchery and getting lit, and honestly, having fun in general. Their idea of fun involves tea or PG entertainment or messing with One Power objects or study or sex with their spouse/warder behind closed and locked doors with the curtains pulled tight and the lights off. Egwene might even dance on the tables if there is Tinker music playing. But Nynaeve and Elayne will be there if you need something important. They're the ones who would write a glowing character reference or trust you with their stuff and let you crash at their place. Egwene would be too busy to take your call unless she anticipated needing a favor from you in the near future, but she'd be happy to exchange spite talk about a mutual corporate rival.
"Sometimes unhinged, sometimes unfair, always entertaining"
- The Crownless
“Tolerance is the virtue of the man without convictions.” GK Chesteron
Deus Vult!
that takes some pretty selective reading