Perhaps the point is that Tamsin/Thomasina and Samantha/Samella are there to fill the gap? But since Mackenzie is a ln and the practice of using a (family, or socially superior)ln as a fn traditionally applied to boys, people find their expectations raised and then exploded. Never comfortable! What fascinates me is that, when fewer given names were in circulation - one or two centuries ago - people seemed pretty happy to use them over and over. Now, with many more names available than ever before, suddenly it's not enough. Consumerism, perhaps?