[bhaak]

If your team is competent and solid engineering techniques are being used, you already have a well working process. Forcing any methodology on this will likely result in a deterioration.

All those methodologies are for the less stellar programming teams, to get consistent results from those (also to a lesser degree to make good and bad programmers work well along each other). Because you can't always get the best programmers.

If Scrum would only work well with good programmers, it would be next to useless.