Barrack Sorting

Depends on what you need and what units you use.
Because I use my 5*s most of the time, Rarity is what I choose.
However, this makes my 4* super-merged units harder to access, so I switch to level sorting to find them quickly.

I sort my own barracks Rarity, Weapon Type, Level. I feel as if that is generally the simplest way to arrange your units, and to find them later, as it would be impossible to just go look in the wrong place.

Since blessings have become a larger part of the game I sort Blessing > Rating > SP with their SP value visible so I can tell when units are ready to learn a new skill at a glance

I sort Rarity > Level > Move type so I can find my units.

I want better sorting options, dangit. =T

By Favorites since i also use my 4 star units and it lets me keep up with units that have good ivs

Personally I go by 1. Favorite 2. Rarity. What this does is it puts all of your favorited 5 stars first, then your favorited super merged 4 stars, then non favorited is sorted normally
This answers the problem people have of not finding their merged 4 stars

I sort by Favorite - Rarity - Reverse Move Type

Sorting by Favorite lets me have the 5*/4*/3* units I actually use stay at the top, and then there is another group of 5* units that are only there for Inheritance or to Send Home eventually are all right below that.
(This lets me separate my important units from the other 200 units I have)

Rarity removes clutter

Reverse Move Type sends the Fliers and Cavalry to the top of the list, so that I can quickly swap my most used classes.

Following this type of sorting makes the game list your army by
5* - 4* - 3* - 5* - 4* - 3*
and I think that this makes it the easiest way to keep track of your units

1 - Favourites
2 - Rarity
3 - Level

It puts all my 5* first I merge order, then level order, and I only have 1 x 4*+10 (Cecelia).

Level only, typically. But I also turned on ignore merges in the options.

1) Rarity
2) Type
3) Weapon Type

I normally sort by level.

I also have mine sorted by rarity. Easiest and best way for me to remember where my units are.

Who needs to sort any other way?

I ain't got time fo dat.