This may be because Buddhism traditionally does not emphasize proselytizing of its faith and as such, expertise required to countered other religions converting its followers are low on their list of priority.

It is about time, the various Buddhists organizations in individual country coming together, and pooling their resources to set up such centralized missionary institutions with the purpose of providing programs that imparts knowledge and expertise for the defend and propagate of the Buddhist teaching, not just to monks but also to Buddhist laymen as well.

Besides the Buddhist teachings, these institutions should include other useful subjects such as leadership skill, conflict resolution, crisis management and negotiation skill in its curriculum. These would allow for a more, well rounded individual able to handle all kind of situations independently. Such knowledge and skill would also come in useful when there is a need for these individuals to support humanitarian and other relief operations as well.

I believe, if there are such missionary institutions existing now, for monks and aspiring laymen missionaries alike, others, from countries that do not have them, would be very interested to a part of its setup.