Growing toms in one half of a grow bag

This is my second year of growing toms, last year I grew all the same variety as I wasn't sure how successful I would be. I grew them all from seed and had far too many plants- 12 in all!!
I grew them in a grow bag with the ring culture(I think this is what its called). I am thinking about just cutting a grow bag in half and standing in on the end this year. Is this method ok or shall I stick to the ring culture method

The ring culture method works well for me and is probably a lot more stable than half a grow bag on end. Toms get very top heavy so the more you can spread the weight the better.