Yes.
And a more recent glaring example would be a Christian NATO bombing a fellow Christian Serbia to help a Muslim Kosovo. I know, I know, you could say that there are Orthodox vs Protestants vs Catholics involved in this scenario but they were still Christians fighting for a Muslim population...
History is full of such examples. Having said that, there ARE alliances loosely based on religion even now.
Coming back to the topic... from a recent reading at a NY Times article, the war is going to be a prolonged one. The Azeris are doing a turkey shooting of the Armenian using drones at the same time Azeris are fighting a war of attrition where Azeri soldiers are willing to die to gain tiny territory in N-K, and that Armenians are getting scared and amazed by the Azeri resolve.
Unless Russia intervenes on behalf of Armenia, looks like Azerbaijan is going to prevail at great costs to the civilians and soldiers on both sides. Very sad to read accounts of cities are full of stench of dead bodies because no time to bury them.
PS. NATO will not intervene for Turkey unless it sees Turkey as a tool and cannon fodder to inflict indirect heavy damage to Russia.