

Not having that rule might be better.
The problem with that rule at Reddit, is that it only exists for the mods, not the users.
So the misbehaving user will pick fights in a sub A, get banned, whine about it in another sub B talking shit of sub A, get banned as well for brigading. Then they go to a 3rd sub C and now actually brigades against subs A and B because their mods invent bullshit rules such as “brigading”.
The unaware users look at this mess and get confused because they can’t recall “brigading” being something forbidden by the general Reddit rules. And while “brigading” is just mod slang for “you shouldn’t incite fights between subs or users” (and anyone can figure it out by searching the word at Google, instead of whining that the mods just like to invent words), there is no rule against this either. Instead there is only a rule for the mods that they have to shut down any user attheir subs who do this.
The consequence is that the unaware users sympathize with the misbehaving one and join their brigade, even if just to taunt the mods into banning them as well. I’ve seen this a lot of times there.

And only you as a mod needs to be that careful. The users will keep going to r/tampa and antagonizing r/FreeTampa, or the opposite, as there is no rule that directly forbids regular users from doing it, only the one directed to moderators.