That the number 6 is a symbol of prestige is the right observation made by dulcimer. A small story:
When my state of Hessen was reigned by a Grand Duke a parade was held on a jubilee, and the numbers of horses were:
- notables and lower officers: 2
- the Grand Duke's family and higher officers: 4
- The Grand Duke: 6
The oldest student corporation of our university sent their officials in a chariot with 8 (eight!) horses. The corporation was punished by a suspension for 3 terms.

Wilfried