So, for what it's worth, here's my extreme Tzaar setup.
What does it mean? Probably nothing. Obviously black is spread pretty thin, though this would not necessarily have to be the case just because one puts a piece on the edge. However, the edge spaces would seem to have less mobility than pieces in the interior. Outer corner pieces have only three directions in which to move and potential access to eleven intersections; other outer edge pieces have two directions in which to move and potential access to twelve intersections. On the other end of the scale, the six pieces in the second-innermost ring which are not in the radial lines (D6, F6, G4, F3, D3 and C4) can move in six directions and have potential access to twenty intersections. Of course, the converse is that these pieces can be attacked from all these positions!
Perhaps what is more important than location is the concentration of pieces. If I'm on the defensive—that is, if the other player is always a step ahead of me in terms of the tallest stack—I would like my tallest stack to be behind a buffer of my other pieces. Player put pressure on each other by executing a capture-stack move where the resulting stack threatens the opponent's highest stack; this is difficult for my opponent to do if I am behind a wall of my own pieces, though not impossible if he attacks this wall then backs away to stack.
The question is, will every game follow this pattern of the two big stacks (most likely tzaar-stacks) chasing each other around until one of the other piece type starts to disappear (most likely tzarras)? Quite possibly. At that point players might need to stack these tzaaras to keep them safe, ideally out of range of the tall opposing tzaar stack. This then might be the critical juncture of the game, the point to which everything builds. In that case, assuming that the players are skillful enough to keep their large tzaar stacks from being lost, the focus of the early game would be to capture the opponent's pieces in such a way that his large tzaar stack is isolated from his remaining tzaaras*, which are in turn within reach of the player's own large tzaar stack, and prevent the opponent from doing the same. A tall order! If this is indeed the starting point for all Tzaar strategy, then we could say that white has a better setup than black in the picture above, because some of its tzaara are well protected.
* Or totts, if that's the way the game shakes out. One needs to keep in mind that players are eating their own pieces when they stack; if a player exclusively eats his totts (that sounds like a line from a highbrow breakfast cereal commercial, by the way), these might end up being scarcer than the tzaaras.
It suddenly occurs to me that a player might well want to eat his own tzaars to build his monster stack. He would be putting all his eggs into one basket, to be sure, but if the big tzaar-stack gets taken I'm not sure that the player really has much of a fighting chance anyway.