The main problem with Broken Steel is that it contains a huge plot hole - why does the lone wanderer have the option of destroying the Citadel with a satellite missile strike when in all the time up to that point the Enclave could have destroyed the Citadel with one button push and won the war against the Brotherhood so why DIDN'T they????? What in the world were they waiting for??????
The very second that Enclave High Command at Adams Air Force Base knew they had lost the Jefferson Memorial purifier to the Brotherhood they should have launched that missile strike on the Citadel!!!
Now if we can overlook that massive crater of a plot hole then we can easily accept another scenario that has the Enclave returning in a DLC.