He's already got all the archmages that he knows he can convince quickly. Trying to recruit more would be an uncertain and slow task, hindered by the fact that he doesn't even know about any except Silverlake (who can't be trusted), and better left to someone with established credentials with such people. Xvim may be trying to recruit more archmages, and it may be worth his time, but Zorian isn't the right person for that task.
Zorian is playing to his strengths - he and Zach both focused on developing their own personal power and skills in the time loop, with friends and allies an incidental side thing. Unlike Jornack, he doesn't have a giant collection of people he's learned through trial and error how to recruit quickly.
And yeah, that pokeball is definitely for the grey hunter. Not sure how he's planning to use it, but apparently it involves a live capture.