"No more free IDs for new Servers" when adding server node in ConfigTool

Dear colleagues!

Within sizing of J2EE instance, I've encountered with the following issue: It's impossible to add more than 16 server nodes upon one J2EE cluster: "No more free IDs for new Servers" message warn me about It...But what If we have a plenty of physical memory on this host, which is supposed to be utilized via a such way, according to Snote 723909 (#ServerNodes = (AvailableMemory / 2.5 GB)).

Thanks in advance for any ideas & tips!

Vladimir