Sadly that is not enough, blocking instances at user level leaves you forced to deal with their users who will spread propaganda in every comment. Defederate? My instance already defederated those 3 but their posts still appear if someone from a sever that aligns with them (I can’t see any other reason to keep a federation with them) crossposts to their instance, now that post will federate with the rest anyway. Defederation should be total, but they left loopholes by design.
And it still won’t matter because not all countries have a no-bullshit instance/comm, so it’s extremely easy to see someone post propaganda about a country without enough users on the fediverse and nobody will know, but if someone from that country challenges it, the users will pile on them (specially if it’s a populist) and downvote them (I can safely say that the only news I’ve seen about my country are goverment propaganda, but lemmy users get MAD if it’s pointed out).

Lemmy as it exists right now must dissapear, it’s designed maliciously to keep the propaganda going instead of fighting it, it’s just the other extreme of Reddit.
I am waiting for PieFed to get more developed to see if it gets better blocking capabilities, because I’m tired of the lemmy loopholes.