New saga with a change of history

I'd like some feedback on some loose ideas I have. I am considering a new saga with Europe not being what it is in 1220. I want to run a more war torn Order of Hermes. So here is the what if (old Marvel reference).

What if a large group of Magi conspired to separate from the order and forged allegiances with some of the noble families and more open minded parts of the Church about 100 years ago? What if then they declared war or the Order? After 100 years of war between the broken factions of the Church, noble families that either sided with or against the Order, Magi declaring themselves kings, and mad use of powerful rituals, magical war machines, unleashed magical horrors and demons Europe is left a war torn mess with a loose peace between the Order it's allies and the sorcerer kings and their allies.

This will be high fantasy in a broken mythic Europe. The Order now trying to maintain what territories withing the various tribunals that remain. Some of the Code is much more lax such as interaction with mundanes. Monsters abound and magical artifacts the order wishes to keep from the hands of mundane lords.

I've only begun considering this as an alternative setting. Is it to far removed from the setting itself? There are a lot of questions I do not yet have answers to, but I was hoping to hear some thoughts on the idea or from anyone who has tried an alternate mythic Europe.

What's keeping the Order together at all, in this scenario? Their monopolies on Hermetic magic and the Parma have been broken wide open, and their ability to enforce a Wizard's March is significantly reduced.

What you also have to be willing to do is change Mundane history a bit too.

Perhaps what we're really talking about is a different kind of Schism war. Instead of it basically being a free-for-all and then "kill the Diedne"... We're talking about a philosophical split between those magi who don't want to intervene in Mundane Events and those who do.

So really, you could have the same schism/civil war happen around 1000 - but the results are a geographic and philosophical divide between the now 2 new Orders.

Lets say the Original OoH keeps it's name, but there's now a rival Order, lets say the "Sons of Hermes". We're also talking new houses here. Why would a new Order limit itself to the philosophies of the Original Founders?

The war ended when the two sides negotiated some kind of truce and geographical divide. That of course, does not stop magi from both sides from occasionally raiding vis sites and other shenanigans.