It's not meant to meet any specific benchmarks, it's simply the set from the VGC analysis.
That's the first issue. That's a VGC 2012 analysis, so it's pretty outdated, and the spreads aren't given any thought. I'll get to that one in a sec.
The main goal of the post wasn't to give everyone a Swampert set to use so much as discuss Swampert's niches and what it can be used for in a team.
To do that, you have to understand why you're using it. To do that, you need to understand what it KOs, what it survives, and what its niches actually do for your teammates. That's what the calcs are for, they help prove the points you want to make to validate its use.
And as for the items, while something like Ground Gem I can understand on the calculations part, something like Sitrus Berry is simply used to give it more staying power, not just on this set but on many others, so why I'd need a specific calculation to advocate its use is beyond me.
Staying power against what? I know not everything is specific like MrE commented before, but it's still wise to calculate big hits and key hits from mons that you're going to see time and time again. Knowing you take two Zen Headbutts from Metagross and can KO back is a very reassuring feeling heading into the battle. It's an upper hand on your opponent and a very good knowledge of your own team, a double whammy.
And why Ice Beam is listed before Ice Punch is that Ice Punch (and Icy Wind) are illegal with Wide Guard.
False, with the new tutors this combination is 100% possible now.
And in terms of the surviving Ludicolo part, Swampert has nothing it can hit Ludicolo with anyways, so surviving a Giga Drain isn't too useful if you can't do anything back (You could get off a Wide Guard, but that would work anyways due to increased priority).
It's more for covering your bases. What if you need to stay in? What if a very predictable switch causes you to sacrifice a Pokemon in the back that you did not need to lose? It's the little things like this that the resist berries are good for. This is also why type synergy on a team is great, but that's going way too far for a simple Swampert idea. It's useful, random HP grass and stuff like that is everywhere too.
However, I do think the edits make a nice reminder on the topic of EVing. I think it'd benefit a lot of people playing Doubles if you perhaps gave some advice on the topic of EVing a mon in Doubles and how one goes about that, since it would help some of the newer players alot. Making your pokes hit specific benchmarks can be even more crucial when your partner might be counting on a certain pokemon to survive or do its job, so it's definitely something people need to keep in mind.
Good call, this is something that I often overlook and probably should put together. I'll talk it over with people and see what everyone's needing the most help with, and I'll focus on that and draw an EVing guide up. It's mostly just calculating the most common hits (can it survive a Metagross Meteor Mash and/or Zen Headbutt? Cresselia Psyshock? Shaymin Air Slash? Tyranitar Crunch? Politoed rain-boosted Scald?) These are simple calcs that don't take too much time or effort, but can provide incredible benefits of an upper hand in commonly recurrent situations.