With a 7ft head height and 2500W+, assuming an appropriate foot print, say 4x8 there's no way NOT to get a pound per with only 2 plants, unless you're totally incompetent. Even if you did nothing in the way of training /pruning and just grew them to 2.5-3ft and then flowered them, you should end up with 5-6ft plants with good bud production with that much light. With canopy training and pruning, 1.5 is easily achievable, better yet fill a scrog net and pull 2 per. Bigger plants and scrog take time. I agree with run more for less time. 8 under that 2500W+ would get about the same with half, if not less, the veg time.