I think Venli is in group 2 for two main reasons.
1 - acording to the newest update all of group 2 is finished and Brandon is considering which character fits the flashbacks better before writing then. Perhaps he wrote all Venli POVs to decide which flashback character fits better with the current day storyline.
2 - Brandon said, in another update, that RoW structure would be more similar to WoK than WoR or OB. He also said that in WoK Kaladin storyline was one group and Dalinar storyline was a diferent group. So same location may not mean the same group.
Group 1 - Kaladin, Shallan, Jasnah, Adolin and another character, perhaps a new POV. I personaly would like to know more about the other Highprinces.
Group 2 - Venli and Leshwi or a new Fused.
Group 3 - Dalinar and Navani.