Trench Height for Terrain

I’m going to be making some trenches but I’m conflicted on how high the trenches should be. Going on a historical basis and the terrain kit FF is putting out it would be 2 inches, but I’m thinking the trenches should be 3 inches because literally every faction has guys taller than the trenches that I’d think they’d want to be concealed assuming they’re the ones building the trenches; mechanized heavies for New Antioch, Communicants for Pilgrims, Bulls for sultanate, etc.

I feel like it would make the most sense for the setting for them to be 3 inches, but I’m concerned about how it may affect the balance of the game. I know it’s primarily narrative but I don’t want for my terrain to throw things off too much (given that the trenches will effectively make up the whole board) compared to what people are used to. Thoughts?