I don't know what you can see, Sg, but I do believe Entropy uses offsite/offforum means of communication a lot so one cannot fully judge based on what is happening here. I'd also like to say that quantity does not equal quality. Anybody looking within the War section can see how many pretty much useless posts the members of Earth post here there and everywhere, congratulating each other to no end, and all round bragging for the whole world to see. Certainly, it is only 1-3 of the members but, if it is any reflection of their secret section, it serves as an example of the different styles people have in forums and demonstrates how quantity does not necessarily mean actual activity and definitely does not mean quality. (I should note that this is nothing personal against the members of Earth but just my opinion with the help of choosing the most prominent example, again, in my opinion.)
While activity certainly could contribute positively to results, that does not mean there are no inherent imbalances between the elements. Of course nobody wants to punish active or actually 'good' teams just because they are 'good' but the reality is, as you alluded to, Masters will learn from the past, choose 'good' teams and the final result of that is everyone being on equal footing as much as the rules and the game allow.
We are discussing whether there is a significant imbalance between the teams considering what the game and the rules allow. Rules such as allowing people to choose which teams they prefer and which teams they do not prefer only serve to emphasise imbalances by allowing active or 'good' people to stick together one way or another. They could of course choose to do the opposite but, let's face it, that's not going to happen is it?
Not attempting to address elemental imbalances just takes away the point of these events because, while certainly any team has a chance to win, the chances are not inherently equal. Such events would not be so much endeavours to find the best team of people but rather endeavours biased toward the best elements. If that is the intended purpose of these wars, to find the best element, then that is one point for such events taking place at longer intervals because 2 months time won't really change imbalances between elements.