IF command rating works like it did in STW, (& I think it does), it takes 1 net victory to go from 0 > 1, for each successive rank the total number of net victories needed doubles, i.e.

Rank . Net Victories
1 . . . 1
2 . . . 2
3 . . . 4
4 . . . 8
5 . . . 16
6 . . . 32
7 . . . 64
8 . . . 128