It might have been seen as an improvised route going down the forest clearing but the two hunters were not that inexperienced to leave everything to just one shot in getting the herd. Prior to their attempt to lead the War Boar Herd to the Lord's Manor, they had already put up quite a number of magic circles in various possible paths the Herd could take as they move down from the forest hill to the opening where the Manor would eventually be.
And the magic circles were all incomplete ones as they needed magic to work. Also, their magic circles were not drawn manually or else the time required to do so would have far exceeded the time they had to get the herd down to the Lord's Manor. After all, they only have a few hours to play with.
Instead, Ress's science teams, especially the team that King Jin personally supervised, were able to create something much more practical.
Magic Circle Stickers.
