This as always been a tricky topic, because of so many variables and hard to police fairly (time zones being a major part)
I know we use to be the AAO police for awhile(yet was still accused of zerging/xrealming/finding the easier fights etc because thats what people do when they have no idea how things really was)... we use to dominate and people swap sides or log out = ghost town = no enemy = no fight = zzzzz = no reward ... so what is the alternative besides also logging out = zzz. It's all about maximising action, and the best action available... winning fights where you are 2:1 ratio in favour can never be described as good action. It should be automatic/default victory via keyboard faceroll.
so we put ourselves in a more unique position to be able to swap back and forth if it was required... did i do it to troll? never, i had some principles of when and how to use it and only did so reluctantly (change from our high geared RR destro WB to our lowbie filler wb on order), yes it would of been easy to troll both sides with almost guaranteed never ending fight. But usually it was fresh zones or if AAO was out of hand / no challenge, and would also tend to inform nrm or cntk in advance. Fighting over scraps was never fun or fair when you massively outnumbered someone.
I know some people would not share similar principles and game the system to maximise their own reward/time/effort/fun and make the problem worse/snowball. It's hard to place blame though because it is their time and it what it is, some people don't like getting farmed and creates the cat and mouse problem but to each their own.
The issue is the easy mode/casual nature issue (both likes to zerg and complain about other when shoe is on other foot) it's really a community/player issue... the amount of people who want easy rewards for minimum effort far outweighs the people who prefer to play for challenge/underdog... so people give up easily / ride coatails of others if they get momentum. Just the fun merry go round that is eternal war
There is little guild pride, so realm pride can't be expected, especially where both sides have each had sometimes toxic elements is asking alot. Especially pre city wars and the need for even higher co-ordination.
I hope the new system works out and doesn't punish those who like to side with underdog.
But if there is no x-realming what will people complain about next and use as a excuse?
I think its mostly a perception and psychological issue. Timezone's dont help, morale and weak leadership don't help... you nail a pug wb a few times, either leader ragequits or gets abandoned by his troops... nobody else wants to step up and lead, creates a partial void... if nobody else comes along, steps up and fills this then puts more pressure on the rest of that realms forces until they break or something drastic happens to turn momentum. If people think the zone will be easy lock they will ironically try harder(casual nature)... if its bit of stalemate, unless semi organised forces are spear heading it one side will eventually get tired and give up unless they have a stubborn leader. Seen it happen alot, people ultimately play how they want and you have to work around it.
I will add a crazy idea which i know you guys will dislike because you want people to grind hard ...
but if population balance is what you desire... there are some roadblocks (and yeah i know they could be gamed) but if they was removed, while your system and giving incentives to underdog to make it worthwhile... then maybe it would be less lopsided.
if there was a option to make instant end game characters for people who just want to t4... and yes i know its not hard to get to lvl 16 and the rest of it for experienced player, but going from decent geared t4 / high rr, to lowbie's can be pretty rough grind if organised and carried, for pug casual even harder... so they are a bit time locked/gated into effort to make it viable if they really really want to try balance things out. Server is casual in nature so for most people that is just too much effort.
So if roadblock of leveling was removed partially out of the equation (like r40, rr 10 so people still need to play and learn it)... then it comes down to pure numbers, and splitting numbers between the two factions and getting the incentives for underdog that you are talking about to eliminate the "x realm" problem to try make orvr more balanced generally like sc's are. Just a wild idea that i will know be shot down, but food for thought if eliminate perception of x-realm is ultimate goal... if barriers was removed and carrot on stick was implemented. And yes i know the knock on effect of it effecting t3 sc's if more people could skip them (which are low already)... and the random pve, but it all depends on what is the bigger end goal.