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Just a moment, where did you find the "skale percent"?
In the external properties of a static object, which are visible when you select this object on the map.

Added 3 hours 58 minutes ago
You need to extract the model from the game, process it in Maya, and import it back.
It seems I can manage without it for now. I found a simpler way. Some models change size if you assign them random animations. The most significant increase, surprisingly, came from the giant's animation: Characters\Creatures\Academy\Giant_LOD-adv.
Here's what I got:

I'll use this on my map.
However, this method is clearly not applicable to all models. Besides, I only checked some animations; there might be even larger ones, but many don't have any effect at all.