Two complaints, one cause. The cards are tall because their height is measured from the longest list on the board, and the longest list is the leftovers — 16 on the outfield radar, 23 on the goalkeeper one. Take the leftovers out of the grid and the cards size to the longest axis, which is Mental with eight. Every option below is drawn at that shorter height; they differ only in where the leftovers go. Real seed data throughout.
The smallest change. It stops being a card in the grid and becomes a full-width strip, so it no longer competes with the axes for the eye or for the height. Chips wrap, so sixteen names take two rows instead of sixteen.
For: one change, nothing moves, and the strip grows downward where there is room. Against: on the goalkeeper radar it is twenty-three chips at the bottom of a scroll, which is a long way from the card you are dragging one to.
The same strip, read as the pool you are drawing from rather than the remainder. It suits the goalkeeper radar, where most of the list is deliberately off it, and it puts the chips beside the top row of cards instead of a scroll away.
For: always in reach, and it reads as a source rather than a bin. Against: on the goalkeeper radar it is four rows of chips before you see a single axis, which puts the thing you came to edit below the thing you did not.
Closed by default, because most of the time you are not looking for it — the answer is already right and has been since the figures were checked against FM. One line says how many, and opens to the same chips. Still a drop target while closed, so dragging onto the bar takes an attribute off the radar without opening anything.
For: the board is the axes, which is what the screen is for. Quiet on both radars. Against: a thing behind a fold is a thing you have to know is there, and what the radar leaves out is worth seeing at least once.
Pinned to the right, beside the cards rather than above or below them. It never scrolls out of reach, which is the one thing the other three cannot promise on the goalkeeper radar.
For: always visible, always in reach, and the drag is short from anywhere on the board. Against: it costs 210 of the panel's width permanently, which is most of a fourth card — the board drops from four cards a row to three.