I was honestly wondering if Flash resulted in Arrow writers being pulled off the show. If that's not the case then it's even worse. At least in that scenario there is an excuse one can point to.
The writers and executive producers didn't change that much.
Though when it comes to the directors, action choreographers and day to day operations producers staff changed significantly enough from season 1+2 to season 3.
The Flash partially benefited in terms of writers and action choreography because of some of the people who transferred over.
They are being stretched thin to an extent and a 3rd project might not do Arrow any favors if they retain the newly hired and the newly promoted people from season 3 in their jobs for season 4.
Cops will gun him down then
When will people learn Diggle's power was needing to wear a mask.