Each Server running tomcat is considered independent and there is no load balancing for tomcat web server level.
If you have a Cisco CSS Router , it can do load balancing for the web servers and distribute the requests to one of the available web servers.
For more information , please take a look at the Architecture and Sizing post in the downloads section of this forum.
https://bobj-board.org/t/86530
EnterpriseArchitect 
(BOB member since 2006-03-23)