Did something similar when I sortied Chitose and Chiyoda to E2, when I already have Suzuya and Kumano already converted to Assault Carriers. Had to make-do with RJ and Shoukaku filling in the gaps for E3 Boss Run. Come E4, Chitose and Chiyoda ended up being replaced by Suzuya and Kumano anyway.
i think it was only me who made mistake, using Shigure and Yamashiro on E1 Hard for ASW.
Already accidentally put in E1 fleetKuritaKurita
Kurita Fleet (green tag)
In E-2, Nishimura Fleet is preferred to open the path to boss node (as higher difficulty requires more Nishimura Fleet members). Then Kurita Fleet is used to clear the map.Patrol unitsShip girls sortied in E-1 will be tagged with grey tagsAccidentally messed up E2 composition