Hi,
We have a similar setup to you, and use a similar system to get them loaded. I also found that blocking off any visually open spaces, helped too, as the brighter ones may get excited by the newness of it all & want to explore. Planning ahead is good and practise makes perfect.
We load the day before too, we have a trial run in the morning & if this doesn't work we still have the afternoon and time for us all to destress a bit if needed. If we have time before the day we may have a few practise runs with them so it becomes a familiar game to them. We don't feed them until their loaded, other then what they get from the bucket lure.
I recently used a similar method to load a Highland Bullock - well just a relay of bucket lures - it took four hours, but I did it - calm, perserverance & positive thinking are essential, I had to send my OH away!
Another trick with the electric fence, is to put a little feed close to the edge of it & then ( prepared for this earlier of course!) lift it over the top of them - you may need two of you to do it so you can do it quickly so that they don't get spooked.
It will be fine,

,
Violet