The thing about Lance is, I did think he was a more interesting character before he was all buddy buddy with Team Arrow. Once he was in on things (I don't mean the early "I'll work with you but don't trust you" stuff. I mean the whole post him knowing about Sara being in the League period) he kind of didn't have a whole lot to do. But the way they've handled his turning on them is pretty illogical. I get that he's acting out of grief and thus logic doesn't so much apply, but it's SO illogical and forced from a narrative standpoint that it's almost frustrating.
Again, I think he's a character they kind of lost their way with and they're trying to take him back to what worked better, but it doesn't really make a whole lot of sense for him to go back there as a character.