Better in what way? What I meant there was just that the "Horde/Size Bonus" does not have anything to do with the number of attack units. Hence the choice of 3 EI vs. 2 EC is not affected by that. I think the most useful way to this about the EI vs. EC comparison is this:
EI's are better in: Atk/Cost (including crop upkeep), More suitable for Ghost hammers due to their speed, Better at farming due to speed and capacity.
EC's are better in: Atk/Production time ... and having #1 Atk/Production time in the game makes them a really Great OFF unit.
EI weapon tier 3 as example is 3x15 attack and deff which equal +45 and EC is 2x20 attack and deff which is +40 for the same amount of crop