Perhaps they are seeking a bit of a challenge, this time? They are thinking of potentially attacking the Republic, might want to test their strength against a world that is ready to defend itself.
That, or there is some plan to make everything easier. I doubt they just decided 'Let's attack Alura' and shipped out to do so. There had to be more planning than that.
Xeth sets down the Nexu's Grin, having made little effort to scan the military defenses back in case it appeared threatening to the Selenians.
He disembarks, wearing his rustic red-orange Jedi robes. He leaves his sonic blaster aboard the ship for now and conceals his lightsaber so that he appears less threatening.
"Here we are then!" Xeth says, coming off of his ship and moving toward the military men in the hangar. "Thank you for allowing me to dock on your world."
"I would like you to take the full importance of this into consideration. We have good reasons to believe that this world is going to be invaded by a large fleet of the Techno Union. Either you make full preparations for this and believe us, or this planet will be invaded and perhaps most of this wonderful and technologically advanced city destroyed. This might sound absurd... But nine Jedi wouldn't arrive here for nothing"