Rhys, my experience of growing Red Kuri and other winter squashes is that they are very vigorous growers and need all the space you can give them. Unrestricted last summer they grew on average 6 metres. They will tend to grow towards the sun (south) and you can move the tendrils to direct them away from paths etc. I think 6 plants in the area you have may mean they are crowded, 4 would be enough and plant 1 meter apart.
I am planning on making very sturdy wigwams out of hazel and training the squashes to climb as I love eating winter squash but resent the amount of space they take up. We shall se how that works.
Good luck
Sue
