I agree with your assessment and just to add to your Houndoom comment, I have gotten a couple in the wild and they are useful against those damn cats (espeon). I find that Gen 2 has introduced a multitude of amazing prestigers. However, I will say that I am in the category of “use it then lose it” in that I love finding 800-1200 CP mon in the wild, then using them as a prestiger and never heal them. With gen 2 there are so many single evolution or no evolution Pokemon that fall in this range. Before it was really just my army of Tauros but now I am able to use Azumaril, Piloswine, Gligar, even Ursaring as fantastic prestigers with a great variety of movesets. When they don’t have a great IV or moveset, I just use em then throw em out. On top of that, they are just plain fun to use! I think this is my favorite aspect of the new Gen 2 mon. As far as prestigers that I keep, they generally have pretty decent IV’s and niche movesets that I use for all the heavy hitters in gyms.
Prestigers
Well, first to understand what i think is a good prestitger is any pokemon with A grade moveset and high attack, mostly with same type attack as himself.
Someone could argue about fast attacks rather than slow, but on my experience sometimes a slow attack is good for timing (i had a venusaur with razor leaf that fits perfectly between Vapes waterguns dodging always)
I dont completely control or searched all the movesets that changed neither i really looked if past trash movesets are now viable or even A grade.
So, anything new or changed with all new patch and gen2?
I saw that houndoom with snarl/foul play can be an option against psy, dont know about fire as flareon and charizard have better movesets, he still would resist eggy psy
I had an army of WG/HP starmies wich now im not sure if they are good, with the new SoB and grass attacks i think that against Rhydon grass types are now better thank to resist ground (not grass/poison)
Wich leaves new Exxegutor Bullet seed / SoB and tangela with Vine Whip / SoB or GK or PW. GK and PW are not so far from SoB and are two bars moves wich are really good against the one bar Rhydons.
Any other good new prestitgers or big changes on prestitging that i didnt see?
Answers
You're right that PW/GT or SoB with either VW or RL (you can fit 2 RLs between waterguns now btw) are the way to go with Rhydons these days. I've also found Victreebel incredibly useful with Leaf Blade, which is highly energy efficient.
I have a 96% Houndoom with Snarl/Foul Play at lvl 30, and it's fun attacking Exeggutors with. I don't see many Exeggs in friendly gyms anymore, but when I do, I grab a Sneasel (love that Avalanche). Umbreon is another effective counter to Exeggutor and Espeon as well as a great generalist prestiger due to massive defense and largely unresisted moves. Skarmory is another generalist prestiger that will do well vs the mighty egg.
For Gyarados, you'll want to look into Raichu with Wild Charge, which is the new king of electric charge moves.
I disagree with your initial statement. High attack does not make a great prestiger - it breaks it.
Because of how the CP formula works, a mon with high attack will have much higher CP than another pokémon with the same total stats, but low attack and high stamina or defense.
So, to get the highest amount of stats while still having as low CP as possible, a prestiger should optimally have high stamina and defense, but low attack. To offput the low attack stat, you want a good attacking moveset, as you correctly stated. Piloswine is an excellent example - high bulk, low attack, and access to an excellent offensive moveset in PS/A, enabling it to defeat Dragonites with twice its CP in less than 10 seconds without dodging quick moves.
Well, also for me ice is something so rare i have to use the only few i hatched. Still Lapras have more bulk and less attack, doesnt have avalanche tough.
Lets say grass... Wich one would you use?
Meganium/ Bellosom or even something like jumpluff?
Or you would still get the eggy/venusaur to do the work?
This is correct. What high attack stat buys is more DPS, so if potions and revives are readily available to you (e.g. live in a city full of pokestops) then high attack prestigers may be advantageous because you can get it over and done quicker. But for many of us, potions are a precious commodity, so more bulk is better for good prestigers. And its better to have that bulk in the form of a high defense stat rather than HP: e.g. Cloyster has huge defence, which means it takes less damage and thus less potion to heal for the same amount of damage done as an equivalent high HP prestiger of similar typing (e.g. Lapras). Well rounded stats with attack a little lower than defense/HP generally make the best prestigers. On top of that the OP is correct that then its all down to great movesets. You want high damage on the charge attack (preferably in short time so that you can dodge), but you also want a quick move that builds energy quickly. And of course you need to take account of typing: the best prestigers by type are resistant to the common moves of the mons they prestige against, and have moves that are super effective. e.g. Cloyster is perfect against dragonite (several highly effective movesets including legacy moves).