Large fleet fights can't be effectively handled in any known way. Synchronizing 1k people for real-time battles leads to several minutes lag for any action (on a good day). On a bad day, the local 'node' will just crash. The total number of updates is something like O(n^2) for n active clients.
CCP have done pretty amazing things for the constraints they were under: real time battles, one shard universe.
Anyone considering learning software engineering lessons from CCP should play EVE Online for a while. I personally prefer my lessons coming from people consistently delivering a working product, and not so known for breaking random stuff that people actually have fun predicting what seemingly untouched stuff will get changed by a patch (e.g. http://www.failheap-challenge.com/viewtopic.php?f=5&t=23... )
CCP have done pretty amazing things for the constraints they were under: real time battles, one shard universe.