Hi, I'm in two top 10 guilds and have 3 worlds. I enjoy playing and most of the time I agree that GBG, in most leagues, is more dependent on the number of fighters you have that can fight, time of day, what kind of goods your guild has stockpiled for buildings, etc.. and there is rarely an issue with map control on this magnitude, but this is clearly a problem and as more people figure out how to do the pattern to accomplish this, it will become more common.
The problem is a bit more complicated than straight out 2 guilds acting as one to dominate the map.
1.) There is an advantage to an all mobile guild over a pc guild or a mixed guild. If you haven't seen this, it's crazy, I've seen fast captures but nothing like going up against an almost all mobile guild. You've got 10 or 20 fighters and it's lagging, you get to your second fight and it's 40 to 10 and that's on auto.
2.) Realistically, any fight where you can ignore supply lines is unrealistic but in GBG, you can fight all the way across the map and have no sectors owned between you and your headquarters and just continue to fight because the sectors on the opposite side of the map might as well be next to you. Think of it like GVG support pool. Why would you make a battlegrounds to include mobile players but take away a key component in prior combats?
3.) Yes, the team up requires a lot of trust and good communication. It's very painful on the receiving end. The best scenario would be for everyone to farm the Battlegrounds but watching 2 guilds do it where half their players have 1000's of fights is a bit ridiculous.
Anyways, I thought 2 of the solutions proposed were good.
1.) Reducing the siege camp %, sure
2.) Increasing attrition gain the further you get from your base (this makes a lot of sense, ex. support pool, etc... should be an obvious change.)
3.) I had proposed in private conversations a long time ago changing the timer for a held sector to 1 hour. It requires a lot of effort to exploit on this magnitude at 4 hours, changing it to one hour would make burnout ridiculous. It won't make GBG not enjoyable but it would make it unrealistic for guilds to dominate when you have to defend every hour