How to change the order of pets.

[Excuses]

It's about a question and also my experience.

I recently got Samael for my twink and lvled up, it was on 8th spot for 2 days.
And I used it for a couple of days with auto-feed on, then realized it was on 2nd spot and a day after it is now on 1st spot.
And also other pets spot was changed too as (I assume!) the order of the pets that I feed more or used more.
(first 3 pets are what I used mostly.)
So I assume if they are at same lvl, the one who got more feed comes up more...because I used Sam in war which I feed him a lot than other two pets that I switched as they get tired.


Can anyone confirm or answer how the pets are organized?

Thank you in advance.