Last March of the Ents Making Last March of the Ents work is pretty simple
Expedition Map is here to find High Market
While this is probably the worst version of Gholdengo in the current format, its damage potential makes it an incredibly fun option for a more casual environment
It's theoretically possible that, if you were to weigh literally thousands of packs to choose your heavy favorites, and bought hundreds of them, you might get a slightly higher pull rate of rare cards than if you bought the same number of random packs - but I don't recommend it, for two main reasons: Most game stores don't permit you to weigh individual booster packs before buying them - mostly because it takes a long time and holds up the line
The deck first starts by casting cards with strong abilities and self-mill effects
Sisus ability goes a bit further, though, because it allows you to choose which card you take, instead of throwing yourself completely at the mercy of a random draw