Mob Pathing

Question about mob spawns and pathing, Im currently leveling a mage and attempting to do the slave pens solo boost, for some reason the mobs on this private server spawn in different locations and path in different areas when compared to the same dungeon on tbc classic, is this intended? did blizzard make these changes originally? or is this because im playing on a private server? thanks for reading and appreciate all responses, cheers.

Ever considered the change(s) between TBC and TBC classic? As far as I'm aware, the mob pathing here is as it was on WotLK 3.3.5.

It is entirely possible blizzard altered, or made new, paths/spawn locations for TBC classic.