@krinid
however... ...disallowed?
In my opinion D and Z are totally allowed to do so. They both recognise the threat by themself, and there's no comminucation between eachother in terms of using the chat or private mail. The only problem is how far both players want to go before they will attack eachother. fully eliminating K will take a lot of turns and in the meantime both D and Z are allowed to attack eachother; the NAP / truce was never officially made (and of course this is not allowed). I do see this scenario happen, but not with an complete cease fire on the borders of D and Z. I think in reality players D and Z will reduce K's income to almost the base income, but not without little skirmishes on their borders.
It's of course a risk of getting strong, players will recognise the threat and react to this. But at the same time there can / will be players that either doesn't recognise the threat or don't border this player. Here's a little example:
Players Z, K and D all have 1 big part of the map. D has the entire right side, K is stuck in the middle and Z has the entire left side of the map and is slowly taking territories from K. K reacts on this by deploying more troops on the borders with Z, leaving some holes for D to break through K's defence. D of course doesn't recognise the threat on the other side of the map and will take as many territories from K as possible. K loses his entire income and eventually gets eliminated leaving D and Z in a 1v1. Both D and Z were playing correctly, K had either bad luck or picked bad. You can consider this as teaming, but again since there was no comminucation between D and Z no one broke the rules.
It will always be hard to tell if players are teaming or not, but assuming every player follows the rules this won't be the case in these games. Of course we do have take into consideration that there are always players who don't really care about the rules, but if possible I want to keep them out of this competition. So far I know from all the players signed up that they do care about these rules, and I'm looking forward to the games we'll be playing together.