The gaps shrink, but only as the beam becomes softer and fatter. It does not look better even though the gaps disappear. In addition, when you align the diodes in the far field you will have to strike a target at some finite distance. No matter how far that distance, it is still finite. You will converge the individual beams so that they lie on top of each other and this also causes the gaps to disappear as they move down field to that target, even if there was no beam divergence.

Norty and I have built many modules and aside from the practical issues of multi-beam alignment, a smaller number of higher power diodes means the near field beam is smaller and can therefore be expanded more while still fitting on the scanner. The resulting lower divergence means a more brilliant far field. Running fewer diodes, harder, might seem riskier, but these diodes are very tough and you will spend a lot more on drivers, mounting blocks, collimating lenses and knife edge optics right up front, with a higher diode count. 8-10W of blue is going to be a lot to balance. You will need nearly as much red and green before you will need more blue.