Hmm two day's ago, i organized an ifrit run with mixed classes. We had someone, who was well equipped, that refused to listen to common sense(tank), and it got all of us killed a couple of times. Once he was gone, we got someone else, who performed better, even though he wasn't perfectly tuned for the task.. tadaa , wins. A few days before that, i had a group with an overtuned mage, who kept pestering about more or less irrelevent details , and ultimately got everyone's motivation down , making the party disband, even though we were performing well. Soo... no thank you. I prefer playing with laid back people , and if it means that they're too laid back to have ultimate equipment for every class they have, then so be it. Weird enough, parties endure longer with cool people, and ultimately harvest more wins, because everyone is willing to work and learn as a team , and isn't frustrated/ stressed as much.. which in return has a positive effect on performance.
You are exaggerating a bit with the level 1 equip example ^^.