This is fine. You can declare any number of targets: the banner, the pawn, other relic(s). Each adds a number of defence dice, so it gets harder. You probably don’t want or need to target the pawn.
Other things you need to consider:
You can potentially move for free using the Buried Giant.
Whistle Pig will probably use Mercenaries for -3 attack, and sticky flame if she wins.
You need to declare now if you are using (paying for) Second Wind.