I usually only see 1-3 mobs on most all maps in low end Praetoria (while playing at x1). I also jog past a lot of mobs (not using stealth) to get to the end of the map to complete the mission, thus avoiding a ton of pointless clearing. Mobs in Praetoria will not follow you unless you attack them or they are a scripted ambush. Only a few of the ambushes you actually have to fight, and a lot of those give you NPC helpers. There really is only one tough ambush and basically you just have to outrun it and try to defeat one guy before they catch up to you.