I really have no idea what you mean by outsourcing because I listed the only 3 games where HAL has explicitly collaborated with another company. Unless you mean outsourcing in general where they hire contract studios and workers to help handle the grunt work which is super common.
Cause Return to Dreamland, Triple Deluxe, Robobot, Star Allies, are all directed by Kumazaki and not in collaboration with any other studio. Even all those smaller titles like Dedede's Drum Dash Deluxe, Fighter Deluxe, Blowout Blast, Battle Royale, etc on the 3DS and Switch are directed by Kumazaki as well.
Eighting developed some of the minigames for Star Allies so technically not: