Well, it is always a tradeoff, decide if you want to run the risk of getting your cap shut down by remotes or not. And the rain of toads spell is mostly only dangerous for nations who have low hp old mages, and no easy access to GoH or the Chalice.
Of course, every once in a while you get lucky and get the pretender on the first try
.
But shutting down caps is always nice. Because at high unrest they also stop producing a lot of gold. Which hits some nations more than others of course. But always consider if it is worthwhile to shut down your enemies cap with remotes.