map idea + questions

so i was thinking my there isnt gmod singleplayer maps that are playable alone all maps are for multiplayer so i had idea making metro 2033 styled map that is about how long you survive example you start in small tunnel city and you have just few guns and you try to collect them and maybe get few npcs follow you to help but i have some guestions is it posible to make hostile rebel npc? and couple ideas to share would be cool

you need to use an ai_relationship entity https://developer.valvesoftware.com/wiki/Ai_relationship and set the subject value to the npc you want as the enemy and the target as !player, you might have to give the enemy rebels a name so that if you placed any friendly rebels in the map they don’t attack you too

Is it posible to just make combine and chance model of it? Or is it posible? and how (if its posible)?

I’ve never tired it so i can’t say yes or no but you could maybe find different skins for them so they look more human on the worksop or moddb site