Let's face it: the inability to convert trade company provinces is utterly unrealistic. As a matter of fact Cahtolic missionaries were extremely busy throughout the domains of Spain and Portugal, and were successful in at least some cases (Goa, the Philippines) and even beyond their domains (the Japanese Kirishitan who clung to their faith for centuries despite persecution and isolation).
I would suggest that two changes be made to reflect this.
First: Leave the current malus to conversion in place in TC provinces. However, introduce new TC improvements that reduce the malus to zero. So like,
- Tier 1 Mission: +50% missionary strength in area.
- Tier 2 Hospital: +50% missionary strength in area (cum. for +100%, missionaries are now fully effective)
-Tier 3 Seminary: +1 Missionary Strength in the trade zone, +1 Missionary
Second: Allow Christians to propagate religion through trade nodes, same as Muslims. That would representation for things like the establishment of the Japanese Catholic community and Matteo Ricci's mission to China. Current events that represent these missions could then be tied to this mechanic -- Kirishitan events for Japan would trigger if a Christian nation is propagating religion in Nippon, for instance.
Also, expand the importance of the Society of Jesus -- Ricci and the very successful Francis Xavier were both Jesuits. All Catholic nations should be able to accept the Societas Jesu, gaining +1 domestic missionary strength and the ability to propagate religion in any* trade node even if they do not have a majority of power there, at enough strength to make at least marginal headway.
*Actually this should probably be limited, because it would be silly for a Catholic England to be spreading evangelising in Central Asia. But the fact that Xavier was making converts in Japan without Spain having any economic pull there needs to be reflected somehow.
Also, other Christian provinces would not be affected by this. Maybe Muslim provinces should be immune too; I don't think Christians have ever had much success evangleising Muslims.
A third suggestion, if one or both of the above is adopted, is to have a Monument or two that boosts missionary strength in overseas (TC, CR) provinces. It could be added to El Escorial (it is a monastery, after all) and/or maybe a new one or two.
And on the other side -- I would say that the Emperor of China, if his Mandate is high enough, can preclude missionary work in his empire. Japan similarly could reduce missionary strength by upping its Sakoku level.
I would suggest that two changes be made to reflect this.
First: Leave the current malus to conversion in place in TC provinces. However, introduce new TC improvements that reduce the malus to zero. So like,
- Tier 1 Mission: +50% missionary strength in area.
- Tier 2 Hospital: +50% missionary strength in area (cum. for +100%, missionaries are now fully effective)
-Tier 3 Seminary: +1 Missionary Strength in the trade zone, +1 Missionary
Second: Allow Christians to propagate religion through trade nodes, same as Muslims. That would representation for things like the establishment of the Japanese Catholic community and Matteo Ricci's mission to China. Current events that represent these missions could then be tied to this mechanic -- Kirishitan events for Japan would trigger if a Christian nation is propagating religion in Nippon, for instance.
Also, expand the importance of the Society of Jesus -- Ricci and the very successful Francis Xavier were both Jesuits. All Catholic nations should be able to accept the Societas Jesu, gaining +1 domestic missionary strength and the ability to propagate religion in any* trade node even if they do not have a majority of power there, at enough strength to make at least marginal headway.
*Actually this should probably be limited, because it would be silly for a Catholic England to be spreading evangelising in Central Asia. But the fact that Xavier was making converts in Japan without Spain having any economic pull there needs to be reflected somehow.
Also, other Christian provinces would not be affected by this. Maybe Muslim provinces should be immune too; I don't think Christians have ever had much success evangleising Muslims.
A third suggestion, if one or both of the above is adopted, is to have a Monument or two that boosts missionary strength in overseas (TC, CR) provinces. It could be added to El Escorial (it is a monastery, after all) and/or maybe a new one or two.
And on the other side -- I would say that the Emperor of China, if his Mandate is high enough, can preclude missionary work in his empire. Japan similarly could reduce missionary strength by upping its Sakoku level.