Yes, i notice it, "trench" is very generic when we talk about defenses that are more than a "temporal and fast made" defensive work, not only are trenches, are strong points to place heavy weapons (MGs) or simple to protect the defenders from enemy "arty rain" and well, to sleep-eat (very diferent a 1914 trench compared with a 1918 trench for example no zig-zag design).
When you are a lot of time in same place humans search confort and a "home" and in many aspects WWI trench lines, the elaborate ones, worked like "fortress" with soldiers being more "a garrison" and not an unit emplaced in X area defending it X time... not a lot movement.
For me in PzC Bunkers-Pillboxes are necesary when defensive works are very strong and made to stay "forever" and you need use hard attacks to hurt the defenders, a WWI defensive line for me are more a soft defense like trenches or improved positions, this is why i prefer remove pillbox in Pacific titles, move bunker as top defensive work and replace it for a new defensive work, an "improved trench" with more defensive bonus (50-60%) BUT not being a hard objetive for units firing it, you dont need AT weapons to attack them.
Japanese log bunkers were surprising strong for a non concrete defensive work BUT not at the level of a concrete bunker, i remember read about the use of 37mm AP ammo to "open" them and when they are cracked use HE ammo to kill garrison, something you cant do VS a concrete bunker, but is true that oposite to other defensive works japanase priorize a lot camo and the first part when you deal with them is discover the target using for example 37mm canister ammo to "clear" visual over them.
Talking about Italy... i remember tha Panther turrets used as bunkers here and i see this more as actual game bunker in PzC (hard target) compared with japanese log bunker systems.
Well, "Game is coming" great know it... maybe we can expect a bone while we wait the J day???
Ok we only now need