Whether its Strategy plan with different packages or Single cycle plan, sequence will be followed.
By creating 3 weeks, 6 weeks & 10 weeks, system will have call objects as per below.
3 weeks - 3rd week, 6th week (can be skipped by maintaining hierarchy), 9th week, etc.,
6 weeks - 6th week, 12th week, etc.,
10 weeks - 10th week, 20th week, etc.,
System can't generate orders based on the previous completion for the time based plan. Try to use Performance based plan by maintaining counter to that plan. So that, system may count from the previous order closed dates.