Planting winter onions and shallots

I am finally getting round to planting my autumn onions and shallots.
Unfortunately for me, I thought the Trading Hut was not going to stock them this year so I went and paid through the nose at Stewarts! Not that there is anything wrong with their sets but they did cost me 3 times the Trading Hut price. If you haven't already bought yours from the Hut, you are out of luck as they have sold out and you will have to go somewhere else.
However, I think they may still have a few Garlic bulbs.

My biggest problem is that I am in the middle of setting up my rotation system and the plot for onions is still occupied by winter and spring brassicas. I managed to squeeze a row of Garlic (Solent Wight), the row of shallots (Jermor) and a row of red onions (Electric) between cabbages and kale, but finished up planting the rest of the red onions and my white onions (Radar) in next year's potato patch. It means I shall be a bit short of space for potatoes but then I usually plant far too many anyway!