I agree. The WS developers can't eliminate latency, but they can probably improve software and server hardware latency and they can account for it in how skills work and players interact. There have been other obvious bugs that lingered for years (e.g. casters running to where they cast dark circle or quake) before being quietly fixed, so it would not be a surprise if there are lag-related programming issues waiting to be resolved.
I made two accounts on two devices and moved the players around the screen to test lag/latency. One device was a mobile phone with LTE connection & the other is a desktop with wired network. I'm on west coast USA using EU servers, so lag/latency should be on the high end. A character on one device could move 1.5 to 2 tiles before it appeared to move on the other device, about 0.6 to 0.8 seconds.
I'm not sure how this amount of lag can generate hamstrings from 6-7 squares away. If my BD and my druid are standing two squares apart, and both start to move in the same direction at the exact same instant, immediately after the server gets location information, my druid could move ~ 2 squares before seeing any movement from the BD and so could see a separation of 4 squares. Meanwhile, if the BD position is updated at the server an instant before the druid, the server could locate the BD next to the druid and able to hamstring. This would require everything to go wrong almost perfectly, a very unlikely case, yet it happens all the time. So, there must be more to it, maybe extrapolation of velocities by the server (e.g. start with BD and druid moving towards each other) or some other programming issues that make this problem worse, e.g. with how the server handles hits when a melee class is "locked on" to an opponent.
Mostly speculation but fun to try to figure out the puzzle. :-P
Good article about this issue here, though mostly from the perspective of first-person shooters:
https://en.wikipedia.org/wiki/Lag#Solutions_and_lag_compensation