The Norigo organ did not entirely fit his calculus, but Ves selected it anyway because of its value in other aspects.
It was the most desirable phasewater organ left intact inside the Arena Lord's enormous carcass. Many biotech research institutions wanted to obtain it in order to unlock the alien secrets to fast recovery and promote the cultivation of human phase lords. Ves would be a fool to miss the option of picking it up just because it did not match his original plan.
He felt that the Norigo organ fit especially well in his plan to become a 'lazy' phase lord.
Ves did not have the time or motivation to engage in more time and labor-intensive forms of training.