If the network weren't at full capacity, sure. But I can believe that with all the interdependencies in the timings of other trains, perhaps a -3 minute change somewhere could have knock-on effects with other commuter lines, and overall represent a more efficient use of the resources.
Too many trains! I'm actually WFH today so I can't be chucked off a train because of points failure, door failure or signal failure. Points failure I can almost accept as the train couldn't physically go down the route it was planned, but the other two were just so that the train could arrive at its final destination on time. Yesterday morning we were thrown off at Gatwick and had to catch a train that stopped at every single ****ing station from Gatwick to East Croydon.