It is quite reasonable to assume that Army Group Center would have taken Moscow by late September or early October if it began its offensive in August, but thereafter would have temporarily stuck in the mud caused by the seasonal October rains (as occured).
It is quite reasonable to assume that Army Group Center would have taken Moscow by late September. It is quite reasonable to assume that Army Group Center would have taken Moscow by early October. It began its offensive in August. It thereafter would have temporarily stuck in the mud. This mud is caused by the seasonal October rains (as occured).