Not showing up to the battle you declared is a terrible way to measure the disruptiveness in my opinion, because real life issues always take priority over a game, and as you may have seen, 1 vs (up to) 20 is quite common with these type of battles - so there's no consideration for attacking 400 forts a year and showing up to all of them as the only attacker.
I'm not in favour of simply applying bans as others have said, not without sending a ticket with a fair warning first, plus banning the particular type of player who gets their kicks from trolling/griefing only leads to ban evasion. But it's the only solution we have and ban evasion itself is a bannable offense, so prepare for an arms race of sorts with new accounts.
Fos' suggestion of removing hats from offending accounts isn't viable either imo, the moderation team should never
interfere with the private running of player's towns, and regardless, you can promote yourself if there are no hats.
The word from innogames is that The West is a "minor" game in their list, and as you all know, markets are being closed because not many people play the game anymore.
Yes we know this well, and we have been begging innogames to improve the broken aspects of the game for half a decade. As @Reino Eno
suggested, this entire saga is simply putting a bandage on the wound, but the company keeps poking us with the sword of a thousand tombolas.
This will then turn to more of the active players from those markets to the ".net" version of the game. Meaning more people will join all the worlds, or at least that is what i think.
That is what we have seen, refugees from dead servers joining our new worlds and generally making over half the players there, but this does not translate to all worlds suddenly becoming active, mostly because it's not fun to start a new character on an established and maxed-out world, frankly more than half of the worlds should be closed and consolidated with character migrations, and also players from other servers that are closing down should be allowed to migrate their character here to our stable fort fighting world. I know that is well out of your hands though.
It might sound privileged or something to a player from the Danish worlds for .net to be complaining about low player numbers, but it's just not possible to fill a large battle anymore on any world on the prime server of the game. Accounts might be "active" in higher numbers but that simply means they have logged-in in the last however many months, not that they are playing.
Forts and duels are the heart and soul of this game, so migrations should happen when player numbers drop too low for the PvP to function. You don't necessarily even have to close the "dead" worlds, just let PvPers migrate our characters, which have been built over years with blood, sweat and tears, to somewhere we can actually play the game.
We used to have closures and migrations when a world's players dropped to 4-5k. Now 400-500 and no PvP is "fine".
It is a tragedy to lose a single player from the game, however it would be a scandal to continue to allow 3 people to hold the entire fort fighting community of a world hostage to their mischief.
So yes, it will have to be a strongly worded letter of warning and then following through with a ban, in my opinion.