The Russians have been reproducing at low numbers for years..... :roll:
In switching over from Italians to Russians, you replaced older queens with new queens. You in many ways, achieved what one of the functions of swarming.....provide young first year queens. So the bees are probably in no way urgent to replace queens through swarming or supercedure as they normally are. Bees will make drones in higher numbers as they prepare for swarming or through the first part of the flow, as days get longer, temps rise, etc. Not sure your timing in requeening, but you may have suppressed all those urges and are benefitting now from requeening by having young, productive hives, with no sense or urge of raising drones.