Complex sentence: It was also revealed that Diogenes had many co-conspirators but that to kill or maim all of them would have been to dangerous for Alexios as he feared that his troops would mutiny if sent out that order.
Split into simpler sentences: It was also revealed that Diogenes had many co-conspirators. To kill or maim all of them would have been too dangerous for Alexios, who feared that his troops would mutiny if sent out that order.