To recover some arguements about Vulpix/Sun;
-Overheat gives you -2 SpA. So it's a -use 1 time, then switch and lose 1 round of sun due to the switch- matter.
It also only got 90%, better than 85% but still not neglectable that it will miss sometimes.
-Fire Blast's 85% is actually very inaccurate. The thing is that you *can not predict* when it is going to hit and when it is going to miss.
It is taking a calculated risk. The upside of that risk is getting a huge damage boost from the sunny weather.
The downside of that risk is missing the fire blast/overheat and getting pancaked in return and down is your sun setup.
You can not rely on that alone.
Draco meteor also gives a -2 SpA. And yet, it is played on almost every special-hitting dragon-type in OU. The -2 is annoying, yes. But the goal is absolutely not to make damage several times. You just want to break through your opponent's team, and to do so, you have to hit hard. And that's exactly what Overheat allows you to do. It's not that important to have a -2 in SpA if your opponent doesn't have anything in his team to take the hit, cause you will then make one KO.
For Fire Blast, now... You have more chances to hit two Fire Blast in a row than to hit one Focus Blast... Ok, focus blast is very inaccuracte but still, it is really often played. And anyway, if you must count on your opponent's misses to win, then there is a problem.
And anyway, as I also said before -and I also have the impression I will be forced to write it several times before it's understood- Vulpix itself
is not the real problem. Yes, it can hit hard, but the real problem is his ability which can offer several turns of sweeping to his mates, and they won't be stopped as in ORAS by the threat of Fletchling's acrobatics.
Also, Vulpix does not get Solar Beam.
Idk why I have to write this in every post.
Then the water point; Rocks & Ground still do 100%.
*enter the obvious Diglet arguement here*( Arena Trapped Vulpix = dead Vulpix = strategy failed)
Vulpix Energy Ball, as I also mentioned before, doesn't Ohko things without 4x weakness. (Onix dies, the rest gets to live)
And the statement "makes XYZ types fear to switch in"; every pokemon does that.
Never said that Vulpix learns Solar Beam and to be honest I didn't see anybody saying that since you first said that Vuplix doesn't learn SolarBeam.
Anyway.
The fact that Vulpix can 2HKO the rock/water mons is actually important. Really important. To be honest, it's almost as if it could OHKO, because it means that
you won't be able to switch safely with water/rock-types which would almost have been the only switch-ins to stabbed-fire-type sun-boosted moves (apart from other fire types, as we said before).
I don't really run into Spritzee that often. Nor Chinchou. Also, 12% chance to 2HKO = 88% chance to 3HKO. I wouldn't speculate on 12%.
For rocks, use defog. Rocks are not an arguement.
I expect you to use defog/rapid spin.
If you lose the field control, then it is a situation brought by your own (lack of) actions, so you cannot blame that on Vulpix in my honest opinion.
Chinchou and Spritzee are both top-tier mons in LC. Tentacool is almost never played. That mon isn't bad by itself, but it lack recovery and that's a problem when you compare it to staryu. And anyway, if sun forces you to run Tentacool even though Staryu should almost always be better, then sun is a problem in the meta.
For rocks, you actually don't always have the choice. Sometimes, the rocks have been placed, you have KO'd the rock setter and then come Vulpix. The thing is that because of Vulpix' power + rocks, you won't be able to send Spritzee safely. And that's a problem too.
The main point about sun is that it is a temporary advantage that can be stalled and played around.
You KNOW your opponent needs to refresh the sunny weather.
You KNOW that once you got rid of Vulpix, the entire strategy falls with it.
Sunny weather is something that you can predict and calculate, and the rest is teambuilding.
Having a staller is as important as having a defogger/spinner.
Common ways of dealing with sun teams are Diglet, Tentacool and mons that cover the most common types fire/poison/grass. Mons with sturdy/sash can take on sunny sweepers.
Especially since HP Fire gets a boost in the sun.
Alolan-Vulpix does a great job in setting counter-weather.
Nothing more fun than actually switching in Alolan-Vulpix into a bulbasaur that was preparing solar beam.
Imagine that sun lasts 40 turns. Would you say that, because it is a "temporary advantage" it doesn't matter ?
Of course, you will tell me that sun doesn't last 40 turns so who cares. But I will answer you "and if 8 turns were already enough ? Wouldn't it already be as if it lasted 40 turns ?".
So yes, sun is temporary. But as sun teams are very offensive, 8 turns already are really long and hard to "stall". And anyway, you will have to KO Vulpix soon enough, because it will come again and have 8 more turns of sun if you don't.
Oh, and there are other sun setters than Vulpix (even though they are far less good).
By the way, if Vulpix dies, it is true that it will be difficult for you to have sun again. But don't forget that, if Vulpix dies, you still have 7 turns of sun. 7 turns that might allow you to weaken your opponent's team so much that you won't need sun anymore to win.