He has had a tendency to... offer himself toward dangerous recon to keep others from venturing out themselves.

[ In the wake of how she and Lup had fared on one such venture, she's reminded now of having scolding Ardyn for even offering. ]

Though that speaks more to his nature to put others before himself, not what he might do to protect himself in that situation.

[ Charming as he is, she certainly can't see him willingly entering a duel for sport especially given what she'd seen in his memories, unless it were in a bloodless game of chess. ]