Stands will always topple preferably in a direction between two legs and directly away from the third.
Below is a quick sketch illustrating differences in stability. View is from above looking down. The legs of the mic-stands are represented by the black lines. Without being staked or weighted, resistance to toppling is all about the the difference in radius between the heavy red circle and the thin red circle.
One leg forward has greater stability against toppling directly down-hill. It's all about a longer distance between the green arrows. But that orientation has less diagonal down-hill stability than two legs forward. Two legs forward has greater stability against toppling diagonally down-hill, but less stability against toppling directly forward down the hill.
Assumptions: Both mic stands are set so that the vertical risers are plumb. All down-grade pointing legs are the same length.
If the stand is not vertical but leaning forward slightly, or even if it is vertical but the center of gravity of the weight aloft is forward of the vertical upright, the center of gravity shifts down hill, and the distance between the green arrows grows smaller. Once the center of gravity shifts outside of the thin red circle, the stand topples on it's own without anyone touching it.