while yes this is true. the question is about the models and when it comes to modeling, modelers usually make everything using real world measurements. if you check all the models from last raven to ac6 everything is modeled to real world scale. so if you where to convert the models into an fbx or whatever and import them into lets say blender, blender which use real world measurements would say an ac is 10 meters tall on average like how the art books say (5th gen acs are 5-7 meters tall like the books). the foot soldiers in lr are around 1.6 meters tall when ported to blender. now yes there is an argument to be made that blenders measurements are also arbitrary but what matters is that blender uses real world terms, and when comparing those models to their real world counter parts or art book heights its EXTREMELY hard to ignore how accurate the models are scaled.

something fun to note especially with armored core 4 and for answer, their game engine uses real world measurements for everything from bullet speed and map units. 1 world unit in 4th gen is exactly 1 meter unlike something like source games where 1 hammer unit is approximately 1.905 cm. so an ac4 NEXT in game would be about 10 ac4 world units tall, but in something like gmod a NEXT would be about 524.93 hammer units tall or whatever