If I understand what you are asking for, my answer (simplified) is to make a blend from two lines, expand, ungroup, and apply a script to the result.
The lines for the blends can be shaped as you like. Best if they have the same number of anchor points.
The script, available here, is adapted from one that is freely available from at least two sources online. The original randomly applies selected swatches to fills of selected paths (search for Random Swatch Fill, or something similar); this one applies them to strokes. Basically, select ungrouped paths, cmd/ctrl + click as many swatches as you want to use, then run the script. Run the script again as often as you like to get a pleasing result.
Peter
