Ever since Regina confronted him about the druids, Merlin's been making more of an effort to correct things. While he knows that Regina is supposed to be another world's version of Gwen, he sees them as two different people, just as he would wish Regina to see him as someone different from her world's Merlin. Like with Mordred, Merlin thinks of Regina as someone that he can learn from. He hadn't really connected to the druids or the Old Religion back in Camelot, and he hopes that doing so here will give them a better chance of being friends.