Andy Markiton's deck had 26 mana sources. Academy produces variable mana, but the whole manabase produces approximately 41 mana. So the average mana per source is approximately 1.5.
So your Revoker or Sphere or whatever are realistically costed as 1-drops (ish). The aggressive Ravagers and Ballistas are 1-drops too. Precursor Golem is a 3-drop. Lodestone Golem is between 2 and 3. Foundry Inspector is reliably a 2-drop and not uncommonly a 1-drop, and can effectively double (and sometimes triple) your mana supply.
That's the real way to think about it. None of this "Black Lotus land" bullshit.
In isolation the Shop 1-drops are comparable to a few things that non-Shop decks have, like Delver. Their 2 and 3 drops are pretty world class. But Shops have no deck manipulation and some unevenness in their manabase so they will pay the cost of more mulligans.
It's not surprising that Oath does well since their 2-drop can outclass Shops' 2-drops. Spot removal isnt a "plan" because there are so many scenarios where even a Swords to Plowshares effectively costs more than the thing it's removing. It can complement a plan though, by taking out some of Shops' unbalancing elements (like Revoker) so that your actual plan can execute. If you don't want to Oath, you need to outclass Shops on curve some other way. I see a few ways to do this already in the Vintage card pool.
By the way, I have extreme happiness that combo is completely crushed by Shops and also oppressed by Missteps. I have no time for the line of thought that conflates the notion of "Dark Ritual is viable" with "Vintage is diverse and healthy".