An issue pops up from time to time how tall should your trees be in a wargame. It matters gravely for abstract line of sight rulesets but is also important when choosing model trees for your true line of sight game
When I started wargaming it was all about the hills. Complex rules were used for how many ranks of crossbowmen can shoot from each hill level and thus you saw the terraced high ground everywhere. Hills were usually defined to be higher then anything else, partly due to the fact that the scale of the battle was meant to be huge where one model actually represents ten or even a hundred man and so the hills were actually mountains.
Gradually over the years games became more and more "real 28mm" scale and thus hills became just a higher ground, way smaller than trees and even castle walls.
The Bolczów castle is totally overgrown and humbled by trees:
The Malbork castle, regarded as the largest castle in the world (a part of it is shown below) keeps up with the trees. Middle Castle's walls are as tall as the trees but the Middle Castle's buildings and the towers stand proudly above them:
If the battle was in the mountains it could be different:
Trees and the city:
So if you plan to use trees in your battles, choose the bigger ones.