The problem is that alliances in general are too cumbersome, unwieldy, demanding and inflexible. A system of treaties on the other hand? A defensive league, a <fixed term> non-aggression agreement, a coalition *vs someone in particular* (in which case you don't need stellar relations with the leader to join as long as you have a common enemy), an opportunity to band together "for this one war" might've been more suitable.
The claims was not accepted in both sides. For example Holy Roman Empire was a German kingdom according to OE. The Russian Empire was also declared itself true Roman Empire also. But HRE and OE didn't accept its claim too.
There were Muslim-Christian royal marriages also.
1st: Ottoman alliances lasted a very long time. The Ottoman-PLC alliance lasted centuries - and it was not reliant on the leaders themselves, nor their religious fervor.
2nd: The system I am talking about would be applicable to more then just the Ottomans themselves.
3rd: The Khanates and Hordes you reference have systems already for them... the Nomad/Tribal systems as devised by Jun allow for alliances with Christians or Muslims ...
There are many aspects of the Ottoman society that differentiate it from the "standards" and thus they really do deserve their own developed systems; this will not be limited only to the Ottoman country itself, but it should enrich the experience of playing such a country much more then exists today.
Aspects of the Sultanate of Women and others, as you well know, influence the entire Ottoman ruling structure... from inheritance to actual exercising of governing.
As far as the need of the Ottomans to pursue the "Rum" legitimacy ... that would be a part of the system, but more of a covert aspect, not overt (imo).
Everything can be done. With a few hundred (or thousand) hours of coding...
Yeah, it was more like a non-agression pact than an alliance.
because I can't imagine alliances with heathens when there is a preacher shouting at every streetcorner about the evils of infidels
so while the ottomans were maybe high fervour, they had high tolerance of christians and that would make it easier to make alliances (and vica-versa, I don't think an alliance between spain and the ottomans would have been feasible )
Just because everyone is capable of having an opinion doesn't mean that nobody is full of shit.
skill that I hate in bloodbowl: dodge, stunty, fend, dauntless and throw teammate
Yes, and the vassals or the people in the millets where so much chioce wether they wanted to be part of the OE or not. Ok, the Empire somewhat tolerated the christian religions but they still built their own temples everywhere.
Mosques were one of the primary buildings of the imperial culture. Many cities grew around them and mostly built in muslim lands. They were temples, but they were also a strong part of imperial cult and its authority with another buildings of the imperial architecture.
The Ottoman Empire was a multifaceted society that grew from the various institutions and cultures of all the peoples it encompassed. It had influences from the steppes, from the imperial Byzantine government, from the ancient and proud cultures of Persia and Egypt - and yes, even from the Catholic Christians it encompassed into its empire. All societies will attempt to spread its authority and morality in all areas where they rule; the Ottomans were no exception.
One of the ways the Ottoman society grew was to incorporate local ruling elites into its governance - and the Ottomans often fully accepted those elites into their culture. However, just as any modern state does today, they had a vested interest to "encourage" the growth and healthy spread of the main pillars of that society. Mosques were (and are) a central hub of society and their spread was essential for that society to thrive.
All societies pursue this and the Ottomans are no different than any other.