Thisd is one is actualy interesting a knowledge worth knowing which most don't with me included.
It's hard having to build a community from zero, and it's also harder inheriting a community with past faults. But as you said, buidling from zero, one must act as a marketer, know the right people to talk to to reel in users, engage with this users so they become royalists who outlast the campaign. Building from scratch isn't easy because you need to always show up, having the right answers to every problem.
Likewise inheriting a community. If lucky, and you inherited a good one, then it's gonna be easy, but having to take over someone else's mess, as you said, I need to observe and not try to shade the previous CM publicly, but accept the project's mistakes, and how we plan to progress further so the community feels a sense of trust, knowing the future of the project is in the right direction.
If I am to build a new channel for Syndicate from ground up. I will major my focus on building channels or mediums where I can relate with users on different issues. As you do over at Discord. I would show up always to engage the first early users and strike up conversations relating to the issue the project's product is trying to solve and in that way, I get unsolicited feedbacks. I talk with KOLs who are not after just incentives but interested in what we have to offer as a product. Relay my observing and feedbacks with the Devs to help streamline the product. Run mini campaigns to bring in users, then I have to go ahead to engage them to be a returning users
If I am to take over a community in trouble. The first thing I do is to learn how the mess started if it's some broken promises, why it didn't work, failed airdrop/incentives campaign. I learn the issue and learn what the team did the first hour it all went sore and start my correction from there. I will have to accept any backlash from the community without playing defense. Then share with them the team's plan to fix the mix. I learn about their core active members and try to engage with them to gain their trusts back so they can come back to defending the community. Plan an AMA since the community is calm when they here a member of the team speak.
I would prefer inheriting a bad community than building from zero. Because, building from zero isn't easy