>>47628117I had this autism forever, the key is to really just look at what relevant meta threats your current mons struggle with and need coverage for, and often this allows for or involves having repeat types, something it took me even longer to accept.
Building shit like a Rain team is one of the better ways to think of this process- people tend not to slap a Fire type on rain teams (generally) not only because Fire is hampered by rain, but because Rain mons, even without rain, don’t have that much synergy with Fire. Water types resist Steel and hit most of them for good neutral damage, and Flying types are often present to abuse Hurricane which means Grass types have an answer. The only positive matchups Fire has remaining are against Bug, Fairy, and Ice- Flying can handle Bug (it’s also often an irrelevant type anyway) and Ice is beaten by Water unless it’s a Freeze-Dry user, which are rare, and those as well as Fairies are also beaten by the Steel types who tend to join these teams and abuse the rain-given Fire neutrality. Even if something particularly resistant to some of your types like Ferrothorn is really bothering you, there’s ways to get around it without a Fire-type, such as Fire or Fighting attacks, or just strong neutral hits. It’s also just one Pokemon which may not warrant making your overall type matchup against everything else worse to cover it a little better. The importance of type balance/synergy varies a bit depending on the format you play, but this logic always tracks whereas abstract beliefs like “Fairy Steel Dragon is a necessary core” don’t always lead you to a good team and may discourage it unless you’re literally copy/pasting good teams with those cores.
