What is the preferred arrangement for prayer in a frontier town (thughr) exposed to enemies?

Primary text

If the town is a frontier (*thughr*), it is best for all people to gather in a single mosque. This arrangement serves to elevate the word (of Islam), strike awe into the enemy, ensure that all hear news of the enemy, and that all are present if consultation regarding an affair is needed or if the enemy forces appear so their numbers can be reported accurately. Al-Awza'i stated that if the matter were his, he would seal the doors of mosques in the frontier areas so that people would gather in one mosque.