I like it. I was thinking that, because both will need some form of stairs, Tech's could be like an Archemedes screw, and Magic's could just make them "teleport" up and down and have some sparcles around the units. There should also be a bold arrow going down when the player mouses over an applicable location, and another simultaniously in the direction which the unit should go when he gets out. Also, pathfinding should be good enough that I could right-click on any place NOT on the wall while the unit is on the wall and the unit should go there. In fact, this should even work with non adjascent (non-connected) walls.
Another thing is that I think the portion of wall you drew should be tower/offence portion. The walkable walls (connecting pieces) are where it shows the "units walk here" thing. Unfortunately, a gate is not shown.
I'm not suggesting that walls are limited to look "Techy" either. That is what my plan tries to cover--possibilities.