What "main team"? Can't be Movistar, as the two teams frequently race against each other.
It is Movistar. The teams are cousins at the organisatorial level rather than brothers or parent/child hence why they're allowed to race in the same races, but Kern Pharma have links to Lizarte which is Abarcá's official feeder at the amateur/U23 level.
Similar to how Orbea functioned as a feeder for Euskaltel but both teams would appear in the same races on the domestic calendar about a decade ago. Of their current lineup, Roger Adrià, Sérgio Araiz, Igor Arrieta, Urko Berrade, Iván Cobo, Kiko Galván, Jordi López, Martí Marquez, Pau Miquel, Iván Moreno and José Félix Parra came from Lizarte, while Jaime Castrillo and Hector Carretero both come down from Movistar.
It's like, this is the staging post for riders who've outgrown Lizarte but they don't want to pick up for Movistar... at least yet. They do still cherry-pick Caja Rural's riders and all, but they have to maintain the relationship with them as an external team which is to all intents and purposes a rival.