Ok, wait - just to make sure I know what you are asking:
For example, if the sequence you had to play was 3-5-7 going up all 6 strings, should you barre your index across all the threes keep it rooted there while your other fingers do all the work?
If that's what you are asking, then I would say NEVER but that's not completely true - you want to cover the strings, but only as a means of muting the ones you aren't playing, not as an 'anchor' to reduce hand/finger-movement.
The problem with the previous approach is that notes can get muddled up together and you lose clarity and definition. By lifting your fingers after every note, the note only lasts as long as its supposed to - assuming you are muting correctly.
Hope that helps