Christian church create GANGS of people WHO'LL sheepishly slaved for their leaders in return for "perceived" JOINT BENEFITS - with support of foreign clandestine services - this could mean HIGH END industries till they run OUT.
then it'll be just LOVE.
so, the LIMIT is 20% but that EXTREME, at most 10% as is the case of Singapore and South Korea before the incumbent Zen Buddhist become defensive AND WILL PROTECT their own turfs.
In China, with the Christian congregation now at 2% of the population, it is still a long way before major friction. IN China, we have traditional Taoist-Confucian dichotomy + Zen Buddhist. We add in the Christian factor - i reckon the size in China can grow to 5% of the ELITE end of the population before major confrontation between TAOIST-CONFUCIAN, ZEN BUDDHIST and CHRISTIAN will appear.
There could be alliances or CONTINUATION of status quo with Confucian is Bureacrat when in government, becomes Taoist when retired, and Zen Buddhist doing "pot shots", will new Christian agenda later!