doesn't matter because the loot is completely RNG, there is no way to bait or trick the game in any way to get more of something, it's all luck.
This is also the main reason why bosses are annoying and nothing more then bullet sponges to finish a mission, they reward nothing.
Ya, but you can kill enemies at a higher rate with the Earth method, so that increases your chances for a better drop within a certain time period.