I think you’re underestimating Picard. Like, not only was the man a wild punk in his youth before Starfleet straightened him out, but it’s shown throughout the series that he’s more than capable of bluffing opponents with access to things like literal time travel.
If nothing else, if he fights Luke, he’s not going to fight on Luke’s terms if he can help it.
You mean the same Luke Skywalker who threw his lightsaber away while confronting the most powerful men in the galaxy on board their planet-killing superweapon? And also tried to talk down the ruthless crime lord who had both his sister and her boyfriend as hostages? :P