When we talk about
what we want CAP5 to threaten, I take this to mean what we expect CAP5 to be good at switching into, and be good at forcing out/killing. This doesn't mean we will always be able to handle every set of these Pokemon, or come into every move these Pokemon could possibly use. The reason for this is very simple, yet very important:
we are talking about Pokemon that threaten one another, not which counter one another. Heatran threatens Volcarona. Volcarona can choose to be able to beat Heatran outright. Not all Volcarona sets can do anything to Heatran. Simply on the basis of type, we would expect CAP5 to be able to threaten: (bolded Pokemon are Pokemon I consider very good switch-ins to have competitively)
Against each of these Pokemon, we either already have or must have a considerably safe switch-in. I have not included Pokemon that are very risky to switch into because of movepool--for instance, it is must too risky to switch into Landorus-T when it is possible to end up taking a U-turn. There are a few more that
might become good opportunities to switch in, but much will depend on other stages. The ideal example is Tyranitar; CAP5 should come in without too much difficulty on a Crunch and threaten Tyranitar out with STAB Grass attacks, but Tyranitar very well have Superpower, and without a ton of Defense, CAP5 will not win that matchup if it is slower. Personally, I think it would be a very good idea to add Tyranitar to the list of Pokemon we would like to threaten, it would go a long way toward not making CAP5 useless against Sand--note the Sand Pokemon on the list above.
On the other hand, we have a pretty obvious list of the Pokemon that will be major hazards for CAP5 on the basis of type. These are:
These basically belong in three distinct groups.
The first group is Scizor, by itself. It's the #1 Pokemon, it's a great opportunity to switch in Ninetales or Heatran or Volcarona. I definitely don't want to let Scizor in absolutely for free, but allowing Scizor to threaten CAP5 is a good idea. Sun does relatively well against Scizor, so it's not a hugely problematic matchup issue.
The second major group is the Ferrothorn/Forretress/Skarmory group. They belong together because while they may or may not present a significant offensive threat to CAP5, they absolutely threaten to set up all sorts of hazards, a major issue for a Sun team. All three are Steel types, the sort we are hoping to reduce. All three allow Ninetales, Heatran, and Volcarona in for free, but at the price of conceding at least one layer of hazards. This is something of a toss-up for me, since this match-up seems relatively fair either way; odds are, the decisions made in addressing Scizor, Heatran, Breloom, etc. will affect this matchup considerably.
The third major group is Breloom/Heatran/Lucario/Hydreigon. These constitute Pokemon that will do massive damage to a Sun team if allowed in completely for free. It is absolutely imperative that these Pokemon
not be allowed to switch into CAP5 for free. Heatran is particularly important in this regard.
As a special note, the issue of Rapid Spin, which isn't really a discussion for this stage of the process, would change the whole issue of threats and switch-ins dramatically, since virtually every Spinner not weak to Pursuit or Dugtrio will allow just about any counter in gladly if it can get off a successful Spin.