In much of the world, it’s SOP for controlling shareholders to be paid a higher share price in a buyout than non-controlling shareholders; the US norm of having a single buyout price for everyone is more the exception than the rule.
NVS may end up sweetening the price for ACL’s minority shareholders by a token amount for the public-relations value, not because they have to do it to complete the transaction.
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”