Imagine how many of these problems would be solved at their source WITHOUT having a chain system entirely.
Just a common drag & select plus the ability to select more than one character at once.
It is a bit irritating, yes, although they'd still need some kind of grouping solution for the console versions either way. Can't really drag-and-select with a gamepad. Although to be honest the only issue I have with the current system is how FIDDLY re-ordering the character portraits is with the mouse when there's more than two party members to a grouping.
