It would seem that both communities need new yeshivas. It shouldn’t be to hard to put down a prefabricated classroom for kindergarten students on vacant land. The setup cost will be minimal especially if they lease the land and the classroom. Then every year add another grade it is doable. The problem is paying the staff, will tuition cover it? Unless you have enough parent paying tuition you are going to have problem covering payroll. I have heard that even wealthy people have trouble getting their kids into yeshivas in Lakewood.
According to the East Ramapo School Monitor’s report estimates that by 2024 there will be 48,000, double what it was in 2014, yeshiva student in Monsey. Where are you going to find the seats for all these students. You will also need to find another funding source other than tuition and fundraising to support it.