Acquisitions generally decimate corporate culture. A lot of the science guys enjoy working for the little guy (under-dog), and don't want to work for big-pharma. Intellectual capital is extremely crucial to MNTA.
Acquisitions may decimate corporate culture if you fully integrate companies. However, treating MNTA as a standalone entity would result in no impact to MNTA's current culture. I hardly doubt anyone has ever accepted a position at MNTA because they thought it was the under-dog versus a company that had the potential to do great things. People may root for the under-dog because it makes a good story however rarely are people willing to join a losing team versus a winning team. IMO, I doubt it would be difficult to convince the vast majority of MNTA's human capital that they could maximize their great work by being owned and supported by NVS's substantial resources.