It depends entirely on your area. How many pokemon spawn near your best stop cluster naturally, how far away from each other are your stops, how many pokemon spawn on the route when walking from stop to stop.
Your best lure spot seems to have 3 stops. Lures generate 1 pokemon every 3 minutes, which adds up to 180 lure spawns if you just sit at this spot, plus whatever spawns naturally.
IF you have another lured stop close to this cluster, you should absolutely walk to this stop and back instead of sitting if the entire cycle takes you less than 3 minutes. This will add 60 more lure spawns to what you see.
If the route you walk to see all 12 stops has a decent amount of spawns and you run incense, you can fairly easily generate more. For example if looping through the entire 12 stop route takes you 30 minutes, you'll for sure see one spawn per stop and another 10+ with incense. Then you would need to catch maybe 15 natural spawns on the way to win the 3-stop cluster and 25 to win the 3+1 stop cluster. The exact math depends on the details of your area.
The good thing is that you still have time to test these beforehand. Test how long it takes to walk through all the stops and how many mon you catch during that time. Look at the potential stop clusters, the changes in spawn density and any smaller loops you could walk through the stops.
tl;dr you need to research your area and do the math.
