I've seen many people (mainly newer players I think) complaining about certain fights being too hard or taking too long, and when I check out their parties, there are often major mistakes such as poor composition of elements, and maybe poor proficiency point allocation. e.g. More than 1 pet set up as a tank, limiting dps. Other mistakes involve players just slapping random equipment (often of poor quality) on their pets without even seeming to have any knowledge of what stats would fit the elemental alignment of their pet. This leads to terrible teams where people have no idea of how stats work, what the appropriate equipment is, and what a good team that can survive situations are. DPS and survivability would end up being subpar, causing many players to get frustrated and quitting the game. I think something should be done about this, as it gets annoying when frustrated players do stuff like yell in caps about something taking too long/being too hard when the problem is their team setup.

Not an official guide but here is a very good one put together by Rixva,,
https://www.sylestia.com/forums/?thread=45988