I understand your point. Do you think that limiting the way they train will save them from injuries, especially those players that are prone to injury. I don't think that if Arteta limits their training time or soften their training will be good, because it might affect some of the players performance. All players are not the same, some are very strong, careful when on the pitch. Some are resistant to little injuries.
Could it be a stepping stone for Arsenal Managers? 10 years ago Wenger was also accussed of overworking Arsenal players and at same time not purchasing players that substitute key players to regain strength. It's not limiting, but changing how they're trained to play in the pitch, it appears exhausting. These players always have injuries ranging from Muscle pull, Ligament, Tendons, Hamstrings etc that eases the notion that the injuries are from aggressive tackling from opponents, and marks excessive training as the main cause.
On the other hand, if the team spend lots of time mastering how to hold ball for a long time and exhibiting sweet football in the pitch, it can be reduced and focused on long passes which would take opponents off the sight of key strikers. Nobody would withstand the way Arsenal plays without trying to rough them, and it happens too often that it then leads to injury, coupled with the training schedule.