Yes, and everyone of those clusters would probably benefit more from hardware-based load balancing than IS software-based load balancing. Also, unless your IS clients are custom java clients implemented using the TContext class, they don’t have any failover benefits at all.
The load balancing support deprecated in IS 6.5 is removed in IS 7.1.1.
From the IS 7.1.1 Integration Server Clustering Guide
[Emphasis mine]
#webMethods-General#webMethods#Integration-Server-and-ESB#webMethods-Upgrade