When you grow them that small it really won't matter too much. They shouldn't crowd each other if they don't have time to grow significant axillary branching. Lollipop at flip and should be fine.
If slightly worried, rotate the axis of lowest retained growth (i.e. not the shit you will potentially prune off). If any axilla does develop, the oldest stuff will grow the most, right? If you have it rotating 45-degrees at each 'station' and alternating how you start each row or column, then they won't even need training to avoid each other.