This coaching staff is in a terrible position. If they start Allen, the know he is not ready AND also concede that they made a terrible choice in Peterman (while letting AJ go). If they start Nate, they probably lose the lockeroom and will be well on their way to the top pick in the draft.
Good luck because whatever decision is made will be the wrong one due to not supplying this offense with what each QB needed. The whole thing is a mess and unfortunately, there is no fixing it until next year. I would start Nate, take the heat and just wait until the gauntlet of death is over (Chargers, Vikings, Packers).