Someone asked about changing campaigns before the game even launched, but my view hasn't changed on the matter.
The ebb and flow of who has control and how "intense" combat is will always change week to week no matter which campaign we are in.
As far as I have seen so far in the guild, very few members even get involved in the war, let alone use TS as is posted to use when they are in the war zones.
I feel this topic is a moot point until there is a regularly organized effort in the guild and not just when it comes to PvP.
I more or less agree with this sentiment, though I will say that AD seems to be entirely absent from Hopesfire. I assume that Bloodthorn is the suggestion because it is now the "official" campaign on Tamriel Foundry? Going to a super crowded campaign might have its own set of downsides - longer queue times being the most obvious.
Regarding the level of guild participation... I think people are probably mostly focused on leveling for now and I anticipate that once a good chunk of us have reached VR content we'll see far more PvP activity (this basically describes my outlook/plan, though I do enjoy dipping my toes into the PvP pool from time to time even while leveling). Additionally, we are also a relatively small guild (with 20ish people online at once being a lot from what I can tell) so even if only 5-6 of us are in Cyrodiil at a time, its still a fair chunk of our members percentage wise.
It is also possible that ZoS may do some balancing/merging of campaigns itself if they perceive the imbalance to be too great for too long (i.e. take 3 lower pop campaigns that are AD dominated, DC dominated, and EP dominated respectively and merge them).
Re: Alliance points, they probably do carry over but unless we wait for the campaign to end (3 months?) it will cost a good chunk of them to transfer.
A possible solution might be to all "guest" a specific campaign to check it out before fully switching, maybe check out Bloodthorn.
TL;DR - I'm happy to go to whatever campaign, but I'm not sure the grass will necessarily be greener.