As i have understood this is not so new. There was an option to test it for se in the test server abd i guess they received a good feedback there. But let's be honest. This was exoected while now wr are having like 650 guys already and it doesn't make sense having only 3 of them in the team.
As well this seems to be only first atep of battle improvements so let's wait what it brings and there might be some nice features. For planning and doibg battles.
But sure i agree that there are some things that are still left forgotten. For example the filtering options that actually make harem screen very slow. As well while making a team this is quite difficult to browse through the harem there. But as well... remember this is an anniversary month now and there must be some good perks and i belive there will be some nice improvements coming in soon because the game is evolving constantly.