Assuming your statue-sniper can leave the group for a minute, you can skip bringing everyone upstairs on any house. It's always possible to walk back, because statues are true-sight only - no sound aggro.
Clipping from the video at 3:33,
Soon as the statue marked with the red arrow turns to the left (north ingame), you can walk behind safely on the blue path. From either the north or south you can pull this area very cleanly without having to wait for additional snipes.
For the other houses, popped statues are in blue. Patroling statues indicated by a line. Red path is the safe zone for the sniper back from the top of the house.
Props to the remapster folks for the high res base map.
Full Size
3rd/House of the Hero: Wait for the diagonal patrol to face away, walk west across the front of the house. Don't cross in sight of the double patrol. If you need to exit east, you can dodge everything except the very last statue the same way.
4th/Zonpa-Zippa's: These are all stationary and look towards the house. Walk behind them, can exit either side
5th/Shantotto: Easy path south.
Purple/North path should be possible, but I've never needed to try it. Wait for the patrolling statue to look away if you do.