Just for clarity of answer, rather than piecing together a few different entries;
Scatter terrain can be removed by 80mm and 120mm sized models.
Defenses walls can also be removed this way.
A regular wall is defined in the app under the Terrain Cards section as "an obstacle that provides cover". Is it the intent that these walls can or cannot be removed by 80mm and 120mm sized models?
(Normal caveats around discuss with your opponent before the game also apply - but looking for a baseline on what could be a game defining moment)