One thing common to all wargames is some type of Line of Sight (LoS) mechanic. It is using this rule that allows you determine whether one unit can see and/or be seen by another unit.
I started playing in Historicals (DBM specifically) and in that game there was no height mechanic and LoS was determined by the ability to draw an unimpeded line from one unit to another. When I switched to 40k the system did have an abstract height mechanic which determined whether a unit could see or not. With the advent of 5th Edition 40k Games Workshop removed it and went to True Line of Sight ostensibly to add a more cinematic experience. I hated the rule in 40k. Nothing ignored me more than having to crouch down to get a "model's eye view" while your opponent justified his shot through a window and two doors whereby his crouching Dark Eldar Warrior with Dark Lance could shoot the foot of your Dreadnaught. Happy Times! That move from the abstract to TLOS was a key reason I gave 40k away.
One consequence of TLOS is that it does away with the "rule of cool" (amazing conversions generally larger than stock) and introduces "modelling for advantage" (traditional extreme example - the prone Wraithlord). Subsequent editions of 40k have maintained TLOS.
When it was introduced into Fantasy I didn't mind as much. Certainly for most players it wasn't and issue - though one local did make an extreme height Skaven Warp Lightning Cannon before being told not to be so silly. The ETC introduced their own Systematic LOS system which seemed to solve a problem that wasn't necessarily there for 99% of gamers. It worked but liked all things that come out of a European collective was overly bureaucratic. Those crazy Danes, ay?
When I moved to KOW I moved back to a prescribed rather than abstract system.
The system seems to work very well without being unnecessarily cumbersome. Now I might be looking at it with rose-tinted glasses because I never found TLOS a problem in WHFB but I think the abstract system KOW uses is critical once you introduce timed games. By having a Height system you reduce any LOS discussion to 2D rather than 3D.
The use of Leader Point gives the measure point and then it is a straight determination.
Again this is a mechanic that enhances the game through its simplicity.