If you want a very active community, start from the ground up. You don’t wanna go and ask your friends from other guilds to be the only people to join your guild (although they are a key piece in achieving success and activity as well). Recruit random level 90’s, and try to train them of course but they will be key characters in your community regardless of pvp skill. Literally the reason my guild averages 4.5k messages a day is because we recruited random people and invited them to the discord. Like Jaxxzy and Pristine said, dumb luck. From my experience, only 1 of 5 members I recruit are actually ever active and only like 5 I have been able to train to be good at pvp.
Just don’t do stupid stuff. Make a good name for yourself.
Prove yourself and then find notable alliances, branch out. Some of our most active members were guests from an ally’s server who randomly felt inclined to join us.
That’s all I’ve got for you, good luck if you make that guild.