I have three sets of grapevines (green, purple, red) each with a trellis setup like in the picture. Each Trellis has two grapevines. I am doing this mostly for fun, anything that grows is a bonus. Should I 1) remove one vine from each trellis and "center" the other vine? These trellises are about 6 feet wide can i get by with that? i would prefer not to add on sideways if possible. A Question about an Arbor...they say it allows more sunlight to the vine, but if the top is covered wont that limit the amount of sun that gets to the plant coming up from the ground? Ideas, suggestions?