In my opinion various one legged postures can be more effective in teaching you how to sink the qi and root
I don’t know really, maybe not for ”sinking” in general, but maybe for rooting. Don’t remember exactly my own progress in detail, but leg strengthening from deep PH practice etc tend to come from more or less single weightedness, or at least the weight unevenly distributed. From what I’ve heard Ben Lo used to say that Tai Chi is single legged and usually dropped down in a single leg squat and slowly rise up again. So he would probably agree.
Except for wuji standing, I do most standing in single weighted stances, even the “holding ball” posture I do is completely single weighted, all weight resting on the rear leg and with only the toes of the front foot touching the ground. And I absolutely love the XY Santishi done with the very most of the weight on the rear leg. Done right it’s torturous, in the beginning most people can barely stand for 12 breaths. But the more you learn to relax through the pain, the more you’ll gain from the practice. This is the one and only XY exercise I return to and practice quite regularly. Not every day, but anyway, it’s the best leg strengthening exercise there is. And it teaches your body how to sink the strength and how to use abdominal breathing better than any other stance practice. IMO.