Why isn't Slowbro tier 1.5?
Slowbro's best defensive sets outperform all Pokemon in tier 1.5. Also, Omastar, even with Rock Throw, should probably be tier 2.5 at best. It's typing is actually pretty pitiful for a gym defender. You guys give Slowbro a neg because it's grass weak, but Omastar is even weaker and has poor quick attacks to add. Rock slide is solid and all, but in the grand scheme of things Omastar has little impact on gym defense. Do you guys even fight gyms or even run/look at the numbers?
Answers
If you take a trip to math city, you'll find that Slowbro stays in the ring just as long as Vaporeon does and deals roughly twice the damage. It's less than desirable attack is nothing to scoff at when you're launching STAB Confusion's.
Also, wasted by Lapras and Vaporeon what? Despite Vaporeon's higher CP, it has a lot more threats than Slowbro does thanks to it's poor quick attack and water only charge moves.
In most simulations Slowbro ranks near the top and in practice Slowbro is always a burden to get through if it carries Confusion. It's very far from trash. If it is trash, Omastar is absolute garbage.
Relevant resistances? Unlike Omastar, Slowbro resists water, which is arguably the most important type to resist in this vaporeon dominant meta (they also both resist ice btw).
Resistances aside, Slowbro has much more bulk. With both of their best move sets, they both last as long as one another and deal as much damage as one another to Lick+Hyperbeam Snorlax. Not only does Slowbro not resist the hyperbeam, but it's also weak to the lick. Despite having every disadvantage in this scenario, Slowbro still comes out on par with Omastar's legacy moveset.
The problem is Slowbro simply has too low of a CP to have any relevance in gyms at all...I fight gyms everyday and have yet to see anyone bothering to put a Slowbro in at all. It's fun and nice and all, but at the end of the day, a mon with a maxed CP of 2127 at lvl 30 pretty much sits below everyone and will get knocked out by any casual player walking by...
Like has been mentioned many many times before, it's NOT how great a pokemon a defender is, but how HIGH CP mons in gyms are.
It doesn't matter if Poliwrath with bubble hits hard, but no one puts them in gyms to have ANY relevance...same goes for Slowbro.
Omastar has slightly higher CP (every little bit helps), but like most things posted, these are their thoughts and if you don't like it, max your slowbro and stick it in gyms...
I actually think Lapras should be moved down a tier since they aren't in gyms much anymore neither and Dragonite is there simply because their CP is the highest so far.
All gym defenders are easy.
The CP issues come down to local meta. In Madison and Milwaukee (two large cities), I'd agree that CP is king, but all gyms in between come down to having the gym at level 8+, coordinating with local team members, and draining the casual, local players resources.
Me and my team mates often place Slowbro and the like (lower end of CP) on gyms where we can because it encourages casual, local team mates to slap on their higher CP Pokemon. If this page's tier list (the most popular tier list) more accurately reflected performance, they could be more inclined to place stronger defenders on gyms rather than Rhydons and Dragonites.
That said, Omastar just straight up sucks and belongs in tier 2.5 at best. Gyarados holds down the fort better than that joke of a pokemon.
Players are assuming thier area is like every other area. CP is not important everywhere. Slowbro may not have relevance in your gyms but they do fine in mine. Many people are putting in lvl 20 snorlax, chanseys, and just random mons below 2200. Slowbro can easily sit in 2nd-4th spot.
Not that placement matters much, if they bothered to get to the gym they are most definitely going to take it down completely.
Slowbro is still a top defender some places. The nerf didn't change much.
I've never fought an Omastar so I can't comment on that.
However with Slowbro, he used to be fairly high up on the defender list because he had pretty good base stats, with a typing and moveset combo that was very very difficult to counter.
Now, after the CP rebalance... Slowbro took a hit to his stats. Also Jolteon and Tangela who both counter him reasonably well got a massive buff. Gyrarados can also just run him over with SE Bite now. For those reasons he's not as high as he used to be (which was Tier 1.5).
He's maintained his spot at the top of Tier 2 because he still does well against Lapras and Vaporeon, and can give Dragonite or Grass Pokemon a nasty surprise with Ice Beam.