To genuinely roll an ML or an X5 (as opposed to it flipping after hitting a kerb, for example) would also be quite an achievement.
Yes, as mentioned above the ESP would probably prevent it. So a fair chance you'd hit whatever you were trying to avoid instead. Better than a rollover accident, but not an ideal outcome.
It's a simple fact that a vehicle with a high C of G can't change direction as rapidly as one with a lower C of G. If you never need to take emergency avoidance action it's not an issue. But if you do, then it is.