So obviously the trick is to not let necro resolve being the landstill pilot lol. But in a case that it does resolve that is by no means game over. If necro is followed up by a draw 7 that can fuel me with some counters or what if the landstill player wastes/strips a land and uses Explosives to clear moxen. Then the combo pilot sometimes must dig deeper. I then can follow up with standstill. The combo player casts duress into the standstill and I draw misstep and trap. What then? I misstep duress then combo gets blown out by trap. My point of this is there are different things that can happen under a resolved necro that can hinder the combo pilot...
If you dig aggressively with necro then burn spells become relevant along with factories. I am by no means saying that a resolved necro is bad or anything. Necro resolving wins more often then not that's a given. But when I sit down across from a burning long deck I am pretty happy myself...
Against Landstill resolving a t2/3 Necropotence is not nearly as back breaking as it is against UW Bomberman/Angels or Grixis for many of the reasons you outline.
Sure, it might not be "nearly as back breaking,' but it's still a broken back.
Resolving Turn 2 Necropotence should result in a win for a competent Combo pilot far more than a loss, as long as the combo pilot is halfway competent. I would also be delighted to play a T2 Necropotence into a Standstill, because that means that my Landstill opponent has likely tapped down on turn two to cast Standstill, and is now relying on pitch magic to stop Necro.
As Josh mentioned, he would counter Necro in this position, and any control pilot, in a meaningful match against a skilled combo pilot, would do the same. You may draw 3 cards, but I expect to be able to leverage my card advantage into more threats than you can reliably counter, especially if you go the route of playing a second Standstill, which would preclude a Drain on Turn 2-3.
The reason behind it is that Standstill creates marginal parity for Necro's draw effect and the deck overloads on Free counters to mitigate the mana restrictions of explosive turns.
Except neither part of that statement is accurate.
Taking the first part: I'm not even sure what "marginal parity'" means here, since that appears to be a contradiction in terms in context. Yes, Standstill generates card draw, but its far from parity. And, yes, Landstill has a high counterspell density, but in the first few turns, it also draws alot of non-countermagic (lands, crucibles, Explosives, Bolts, Jaces), The chances of a Landstill pilot having a sufficient density of counterspells to stop what the Necro player is about to unload is unlikely (although not impossible). Furthermore, if the Standstill pilot plays another Standstill to draw more cards when the Necropilot goes off, they are almost certainly going to be cutting off a Drain (which is one of the most common counterspells in Landstill).
And, while Standstill can be chained into Standstill, like a pseudo-Necro, it is different in two respects. First, it requires mana -- a precious resource at these junctures. And, second, it has to be drawn. Playing T2 Standstill and having or drawing another Standstill in your first 12 or so cards is far from a given.
Second, yes, it has alot of free counters,but I would say it's "overloading" on them. Josh's NYSE Open deck had 8. 8 is not "overloading" on countermagic, whatever that might mean. Moreover, 8 free counters in a deck is not enough to stop each of the spells the Necro pilot is about to unload, especialy if they play Standstill, because in a deck of 60 cards, that's one free counter every 7.5 cards.
I've beaten more Necro's than I've lost to on the modified version of Josh's list that I used to run.
I have absolutely no doubt of that -- but that just speaks to how bad your opponents were. I've won countless games in a range of archetypes that I shouldn't have, but for my opponent's being terrible.
I've seen Dredge pilots lose games they should have won because of missed triggers. Necropotence is a ridiculously decision-intensive card, and introduces probably more or as many opportunities for error as any card in Magic (you have to decide when to play it, how many cards to set aside, and which to keep, etc). Cards in that class include Doomsday, Top, Jace, and Gifts. A non-desperation Necro should never lock its pilot out of the game barring truly unusual circumstances.