I think it's quite difficult to make the case that this would make the regime more or less strict. Because of the differences in the way the systems are established and the processes by which they operate, I think it's very difficult to say this would create a stricter system.
The issue on productivity is perhaps a bit distinct from the question here in particular. There is literature that speaks to the degree of a firm's size and market share, that speaks to their innovative capacity and their ability to manage supply chains effectively. There are, in any event, balances that need to be struck between market power and efficiencies that can be gained from size and scale versus the importance of maintaining effective competition.