Yup, If you are doing what is called square spacing, then you will have points that will have upto four heads hitting the same area. But if you use triangular spacing (where each row is offset from the previous row), then you'll usually only have spots where three heads are hitting. Given that I've never seen very much that otherwise addresses the issue you bring up, I guess it's just treated as "wasted water". I.e., it's better to design where some spots in the lawn will get too much water than to design such that any spots get too little water.

A search using "How to move in-ground sprinkler head" -- but no quote marks-- brought multiple results, both text & videos.

I have two systems - the rainmachine (8) at my rental and the orbit bhyve (I think it's 12) at my house. Because I've been dealing with reseeding off and on for a couple of years (note, fix any broken sprinkler heads first), I've had my rental/RainMachine on more me-controlled rather than weather based. Remote access is awesome, I definitely have to say, since that's allowed me to tweak the schedule based on the rain predictions (since seeding requires more than in maintenance state, and I guess a ding would be that there's no "seeding" choice for the plant type, but doubt anyone has that). I chose the rainmachine about 2 years ago based on the fact that I wanted a controller that didn't rely on the company being an ongoing entity - one of these companies WILL eventually go belly up. It's been working great for me in this scenario, though I do currently have an issue with remote access on it, but I think this has more to do with my tenant's internet connection and I haven't had the time to troubleshoot it with the holidays keeping me busy. I literally have not had to open the weatherproof box I store it in for the last two years, so much so that I've forgotten how to use the buttons on the device (of which there are really none, being the 8 version). For the B-Hyve, I've had it for about a year and a half, and have it using SmartWatering (weather based). I did purchase a sensor for it at one time, as that was required in order to get the Water District rebate (so this one essentially cost me $0). I will give it much credit because all my plants and grass are still alive relying on it to make the watering decisions. I have definitely seen it skip in periods of rain (we are in Northern Cal, in a perpetual drought, but saw record breaking rain last season). The app can be a bit quirky - like it will have watered that morning, but the rest of the parts of the app need to be caught up on this info like saying tomorrow it will smart water, but wont end up actually watering again tomorrow because it does eventually catch up. It's gained my trust (to water as well as not water), so I've been able to look past that. I am currently having an issue where my front yard zones are not turning on, neither on the app or directly at the controller, but I'm guessing that this is also something unrelated to the system (like I probably need to check the wires) and again, havent had time to troubleshoot it (not urgent since it's almost winter), I will say that the b-hyve having knobs is nice, as I know the gardeners could probably test the system if need be, while with the rainmachine - the tenant's gardeners doubtfully have loaded the app on their smartphones! And I guess the b-hyve gets points because it comes in an outdoor enclosure (had to make my own for the rainmachine, since I needed it to be outside of the tenant's dwelling). And since it's orbit, you know they are not going anywhere anytime soon. A ding with B-hyve is that I don't find much online/in forums about it for troubleshooting - not sure why orbit wouldnt sponsor that so that people can get the wisdom of the crowd. I say with either of these two, you probably cant go wrong. The rainmachine is pretty, so if you plan to have this in your house, I'd chose that. I guess I would say I like the graphs of the rainmachine app better, but that may be unimportant once you just have it at set-it-and-forget-it state.

So my drawings of the arcs are probably not true to scale. The zone that is in question has 5 heads in the line. The radius of the nozzle is about 25'. They are all Rainbird 5000 series. Distance from sprinkler #1 to #2 is about 21'. Distance from #2 to #3 however is just over 30', as well as being nearly 30' away from the sprinkler heads along the back edge of the property. The area that #2 and #3 cover is also sloped so some of the water is lost to runoff. #3 is about 25' from #4 but is in a flat area and has decent coverage from the two other nearby zones. The last sprinkler head in that zone is also right at 25' away from #4, but is in a flat area and is only about 10' from an R-Van Rainbird rotary sprinkler head as well as only about 15' away from another rainbird 5000 (which only has a half arc so it puts down twice as much water over the same amount of time.) That area is also between my house and my neighbor and ends up getting shade most of the day. Because of the R-Van rotary and the 5000 series being so close to that last sprinkler, that area ends up being over watered. My biggest question is whether it would work to cap off that #5 sprinkler head and add a new sprinkler head in between the current #2 and #3? I am just trying to figure out the best/easiest solution.