Don't know anything about this Luan, but when people say, "I'd rather keep Munir", I think that's all I need to know.
I don't rate Munir AT ALL and would rather we just change formation and have only 2 of the 3 upfront (if there's an injury or wtv), per say, and put in someone capable elsewhere on the pitch. It's not like we play with a set front 3 in-game formation anyway, since everyone keeps changing, depending on where Messi picks up the ball etc. So, in important games I would just put on another midfielder and do some reshuffling (which sounds drastic, but it's something we do often in game anyway); in less important/irrelevant cup games Munir can start all he wants, I'm fine with that.