Outdoor WiFi mesh topology vs. repeaters
Solution 1:
You have too many AP's! If you are receiving that many disconnects (I assume from barcode scanners like, Datalogic Falcons) then you are doing something very wrong with your AP placement.
What you need to do is trim some AP's and add antenna to each of the remaining AP's to increase the signal range instead of adding more AP's. More is not better with access points because you're going to confuse the scanner guns as they have -db threshold for when they will roam. I think whats happening is as signal strength fluctuates (which it naturally does) the guns keep jumping from channel to channel trying to stay on the Access Point with the best signal strength/quality. The guns/pcs will keep track of what AP they are connected to via MAC address, so adding antenna increase the signal strength without increasing the number of actual AP's that are in the area. Keep in mind, and this is VERY important, that when you add antenna there will be two per AP and these two need to have line of sight with each other to be effective. I have seen professional installers mess that up.
Another thing you should be aware of is meshing your AP's will cause latency and quality issues as you add hops. This may cause an issue if your software makes use of a chatty TCP protocol (so check how latent aware you software is first). Meshing your AP's is good if you can't get a wired connection to a location or for fail over. In this case I don't see a mesh topology helping you out... Not to mention your root AP's may bottleneck.