Increasing the size of the zone ... (STALKER: Call of Pripyat)

Hello. Can anyone write, say or show (video) how to increase the spawn of all living things in the game? In the original, without mods and other things. I found the same question somewhere, but did not understand. They explained that you need to edit the squad_descr.ltx files. npc_in_squad. But it does not describe what exactly to change, how much so as not to overwhelm everything at all. And just slightly increase the number of NPCs, mutants. If anyone understands what it is about, help to do it. At least with a detailed explanation.