It's an appropriate name. First, we have the dichotomy between the past, Janus Zeal, who is for all intenets powerless, with the future, Magus, whos power is almost without parallel. Then we have the dichotomy between Magus, who is fixated on the past, and the Prophet, who is fixated on the future (relatively). Yeah, I'd say it's appropriate. The Wiki article indicating that Janus was worshipped for harvests correlates nicely with the scythe, which is a tool used for harvesting.