You can use on paid Zoom link for a few classes

 

You are running your seminary with say up to 100 students. All you need to do is to pay for one Zoom account for up to 100 pax. 

        Here is one example: Set up one Zoom meeting from Mondays through Fridays from 9am - 2pm. This is assuming that you will be having different classes during this period. 

        Create the Breakout Rooms. You can name the Breakout Rooms according to the name of the lecturer or the module that they are teaching. 

        Once the student clicks on the common Zoom link (or enter the Meeting ID & Passcode) for this Zoom link between 9am - 2pm, they will be able to choose which class to enter.

        If you have 400 students in your seminary, then you have to just purchase your Zoom package to accommodate up to 400 students. 

        Technically, it would not disrupt the quality of the connection when you have a 399 students in a 400 pax package. Poor connectivity will only occur when the bandwidth (I think at either the host or the students' end)  is not able to support the 400 pax package. 

Easy!