best capture?

I could take his biggest die, showing his largest value -- but there are at least two potentially valid reasons to take something smaller. Are they persuasive?

Tournament #13561: Friday Soldieralikes Current Round: Round 1. (organized by irilyth)

They look like Soldiers... But they're not.

Skills in this game: X Swing

Player: ElihuRoot *Dead Dude* *Fanatic*
Your Button Man: RandomBM (8 10 12 12 X) Score: 17.5 (-9.6 sides) Rounds Won/Lost/Tied: 2 / 0 / 0 (Out of 3 wins)
Your Captured Dice: None

8-sided die	10-sided die	12-sided die	X Swing (with 5 sides)		12-sided die
5	2	4	2		9 Captured last turn
4-sided die	4-sided die	8-sided die	10-sided die	X Swing (with 14 sides)
4	4	6	7	7

Opponent: Limax *Wombat* *Is a MAN* *Fanatic*
Button Man: RandomBM (4 4 8 10 X) Score: 32 (9.6 sides) Rounds Won/Lost/Tied: 0 / 2 / 0
Captured Dice: 12-sided die