This is known for many online games, since animations and effects from each player fighting ,makes much more stress to the engine compared to them just standing still.
This is actually an incorrect analysis. The server itself does not bother itself with animations and effects, that is purely client side. The server only handles the flow of information. It doesnt tell the players computer how to render each effect, it simply tells the computer what was used, where, and for what effect (plus a few more tidbits but to keep it simple this is essentially the servers job). IDK what is causing it to backup on itself in large scale PvP within semi instanced locations, but somewhere there is a bottleneck to the flow of information.
So far we know that zone changes of any kind cause extreme stress on the server. When Auroria land changes from normal land to housing provinces, the server gets sluggish and cannot process much information (or at least, enough to keep things smooth). When the area around a castle becomes "instanced", forcing unrelated players out and hiding buildings, the same thing happens. For some reason the change in landscape causes the servers to back up on itself... if there is something to be fixed (that can be within the engine at least), this is probably where you would want to start.
The last potential is that it could very well be client side as well with a limitation of the engine as you said. Information might be bottlenecked on OUR end rather than the server end due to how the processing engine was designed. Cryengine 3 was never actually made for multiplayer purposes, but rather for great graphics in singleplayer games and realistic physics and animation effects, sacrificing as little performance as possible. Obviously it CAN be used for multiplayer, but thats a byproduct of demand more so than intended design. But as I was saying, it could very well be a limitation on the client side on how much information is allowed to be received and sent at once. This does make sense since people who were not in Auroria during the housing changes felt less (but still felt) lag than those who were there witnessing what ArcheAge would be like if it was a turn based strategy game.
My bet? Its probably a mixture of both.
Yes, you should reduce numbers to 50 on 50.
40/40 would make it a lot easier to keep control of your members than 50/50 leaving 10 odd balls out for the main raid.
