I have been attempting to quantify enemy difficulty and loot drop rates/ loot quality.
Until recently, my team size was limited to only two players at a time. The primary farming location was the floor which featured Uranus bot, his associates (hacked loaders), and one occasional Very Badass loader. My team consisted of one fighting character and one mule. Gaige was the battler. Depending on how sloppy I played, one to four hacked loaders would invade the corridor leading to the elevator. A very badass loader would only show up once or twice in ten rounds. No big hassle keeping everything in control. I would estimate that the legendary and higher loot drops averaged around one per round. There were rounds where no Eridium dropped.
Then I added a third and then a fourth team member. Gaige got replaced by Sal. No additional humans, just me playing with 4 controllers and two monitors. Eridium was plentiful and never absent with 3 or 4 team members. As for the all important legendary and better gear, they usually increased with team count and level. Here are the drop quantities per 10 rounds:
This batch consisted of one level 80 (Sal), one 78, one 72 and one 38. Only Sal did any fighting. Leveling was going on during the 40 trials.
The results are encoded as follows- each digit is a count of legendary or better gear in a round. Average drop rate is 1.35 per round. The falloff on the fourth batch may be due to team strength and Paul Hellquist’s warning about lower drop rates with stronger team composition. Or it could just be due to RNG.
Enemy difficulty is hard to measure. A ballpark estimate is 10-25% stronger for each additional player added. I base this on the amount of ammo consumed, whether playing solo, two, three, or four players. The standard deviation on ammo used is high. This is due to random bad shots from the Sand Hawk.
There was a big difference between additional enemies present when I was playing Gaige vs. Sal. Because Deathtrap was not on the front line with Sal, there was almost no penetration by hacked loaders or the very badass loader. More and better enemies vs. player count was only a problem with Gaige plus one or two additional teammates. When Gaige had two teammates, we were subjected to two FFYL episodes, which never happened with just one teammate. The gal or DT seem to attract trouble!
There is an open question (enemy strength vs. team size) on the web, and may only be answered with calibrated weapons and enemies. My tendency is to attempt to level two or more characters at the same time, and I wonder if I am shooting myself in the foot with this strategy. What if this technique results in longer battles and increased death rate?