Not to derail on the "other" of my personal crusades,
I started playing Wasteland3, and while it has similar unfortunate movement system (you control on character and the rest follows) it has far more flexible grouping system - select/diseellect all is there and is bound to space (because it is kinda important), but on top of that you can quickly create smaller groups either by boxing with mouse, or SHIFT-click on portraits (I think ALT is used remove from groups but am not 100% at this moment). TAB is used to switch between characters within created group, or you can click on their portrait to set them as leader.
“Following” is still a problem (twats lagging behind and then taking a shortcut through a mine, etc) but the grouping it more efficient and more functional then what Larian has at the moment.
I think it is something Larian should take a look at, as it doesn’t fundamentally (I think) change control scheme into RTS-like one, while provides handy option one would expect from party based game. Group/ungroup is there already, and it already made the game way better. Now they need to figure out better and more reliable grouping.