Resolution:
On the Broker Admin page, it is possible to add the Max Engines column and then enter a number to create an upper limit of how many Engines are used on a Broker. However, it may not always limit the number of Engines used. This can be from two different known issues:

First, the Engine count is not updated in the Director when new Engines log in to Brokers. Therefore, more Engines may be allowed to log in before the Brokers report the updated Engine count. This is a known issue in GridServer 4.2, up to Update 11. This will be corrected in a future update.

Also, when the Max Engines setting is lowered while a Broker has more busy Engines than the new value, the Engines will not be logged off until their tasks are finished. This is a known issue, and the correct behavior.

Max Engines Setting Does Not Limit Number of Engines