As long as you move the line across you'll be fine. Many people grow like this in small plots.
A veg row - - - - - - - - -
B veg row - - - - - - - - -
C veg row - - - - - - - - -
Just moving A crop to B position, then B to C etc. The order of rows doesn't really matter, just as I said, as long as you don't plant something of the same family after the parsnip, eg carrots.
If a certain crop needs 2 rows, then move everything along by 2 rows.
Just making sure that you don't follow one veg family, with something of the same family.
My own garden bed has, a row of runner beans, row of swede, row of early potatoes (followed by leeks in the same year) and a row of winter cabbage - the crop row just moves across the bed through the years. Rotation on a small scale