Having luck means picking something randomly and throwing that in the tank without much knowledge or understanding.
I'm not very good at being lucky
My approach is to learn from the ppl who have the know how; so I go to the goldfish board for goldfish keeping; to the snail board for snails; and obviously to the plant board for plants.
One of the reasons aquariology is interesting for me, is that you need to learn a lot of things from different disciplines and synthesize several (sometimes conflicting) approaches into something that works. (Many) others prefer to become experts in a limited field.
While it's true the planted tank ppl have their tenets, and some are so focused (or biased) that they end up resembling integralist audiophiles, in the end every community has ppl like those. Some just need to have dogmas so they feel like they are doing the right thing - it's a good feeling, knowing that you are always right.
Regarding gurus, as I have called them, they're obviously neither gods nor infallible. Sears and Conlin have been gurus for some time too, but then someone made one step further and suddenly their work became outdated (not that PMDD stopped working anyway) - It's all about looking at things they say with a critical eye, so we do not end up being at their mercy.
I don't think Walstad or Barr are infallible, they did their homework and their tanks work (Walstad actually has an approach that's not entirely different from yours) - and their business model is such that they don't profit from the chemicals we might be tempted to buy.
(On a sidenote, my tank has all easy plants in it. Even with low lights and no added CO2, there's so little K in my tap water that the leaves would always end up looking like a sieve. Talk about luck!