Don't understand why Arreola left Ronnie Shields...?

I feel like Arreola and Ramirez are good but not great for each other. Arreola respected Shields and his training regimen underneath him a lot more then he did with Ramirez. Chris came in lighter, quicker, sharper underneath Shields. I'm not sure when he left shields but that fighter that came in this past Saturday was a lot different then the 2011 Arreola. I don't know his record underneath Shields but damn really think it was a big mistake moving back to Riverside from Houston to train again. A lot more distractions and less discipline. Look at how Eric Molina did against Tony Grano last Saturday. Grano is an above average heavyweight who lost to Molina and Molina was KO'd by Chris in 2 minutes! If anyone knows when Chris left Shields please post.