True. I don't think grudges help anything and If they are offering us decent deal, why not take it? (Not saying we should do this deal, just talking about grudge).
I think it shows small team mentality If you keep bitching about someone taking your player. Get over it. We will get another world class player like Neymar in few years. No big deal! Look at history of FCB.. We have lost so many times one of the best, but always found new one. That's Barcelona!
We have fucked that relationship ourselves by chasing first Thiago Silva and then Verratti when everybody knew we wouldn't get them (and didn't buy anyone else, therefore hurting ourselves).
I think we should hold a grudge and only deal with them if we can damage them severely, like picking up Mbappe for free when he expires or something like that.
We should deal with them as we do with Real: Only if it is in our benefit and their disadvantage or to damage their image e.g.
I would have been so mad if the Di Maria-transfer had gone through: Helping them financially and getting an older real-player (who might could be useful, but not more than any other player out there).