Always try to grow in the tallest space available, but beyond that, if you are creative enough with your lighting style you can grow on any shape footprint!
Focus on giving your plants lots of overhead lighting, and then as they grow, be on the lookout for dark, dim corners that could use supplemental lighting.
And of course remember to save yourself room for the serious stretch that happens during flower.
I'd start at least 4 seedlings becaus eyou don't want to get to flower and discover you have no females, and that way, you can pick the healthiest one to finish.