I know we have the ability to make groups, which is great and wonderful.  However it would be nice to be able to rearrange my pets to my liking instead of the default highest lvl pet.

Full support.

I have actually created a thread about this (and about the option to sort inside the Reserve) a long time ago. I'm just linking it to add to this thread :D

Could you please describe the full logic for custom rearrengement? Timain's idea is quite clear but this one is vague.

For example, I have 2 groups with custom sorting. I destroy one group and move the pets from it to another group. What happens with my custom sorting in both arrays? Does it disappear for the destroyed group or for both of them? Or does it overlay somehow the sorting in the second group? If yes, then how? Do I place first pet from one group after first in another, or place all the pets with their custom sorting after the pets from another group (or before them)? Or something else? 

And same problem for all other cases when moving sorted and unsorted pets to soryted and unsorted groups. It's impossible to code something without having full and precise logic, and right now we don't know how do you expect it to work.

Well, what i was thinking was to have the ability to drag and drop pets in a certain order. Groups would still exist the same way they do now (although they too could use a drag into placement feature). Groups would still need the manual 'move pet to this group' button.

When you would move new pets into an already sorted group I would have it set so that all the new critter get moved to the bottom or end of the group.

The custom arrangement  of a deleted group would be destroyed upon moving the pets, or, if it is easier to code/more perferred by players, the destroyed group would keep it's custom arrangement but just be stuck at the end of the new group.

When moving sorted pets into groups with unsorted pets i would probably just leave to default sort everything or maybe have all the sorted pets just get shipped to the end like with the sorted pets into sorted pets.

I hope that made more sense. This is at least how i would have this set up. I am not a coder, i don't know what is possible and what isn't. This is a suggestion and many of this could be altered depending on what the other players here think or would perfer.

I support this as well. It would be much nicer to be able to 'order' pets within a group. For me personally, I'd like to keep breeding pairs side by side or order non-breeders by color, breed, or even power grades. The options are kind of limitless with how different people organize in different ways. Gryphonfire worded their explanation well.

I know it would probably be a big chunk of work to take on for whoever has to code it to make it functional, but in the long run, I believe that it would make the site more customizable for each person's style of gameplay and preferences. That's a powerful lure for me when I'm considering joining a site, and I'm sure it helps make other user's choices when considering becoming a member or continued involvement with a site as well. 

Being able to order the groups and move them around would be nice too- I don't like how they are static and that the tabs for the groups can't be switched around. I more interested in gaining order for pets first though. n_n

For me, the whole concept isn't a pressing issue that I want resolved immediately, but it would be good if it could be implemented in the future at some point.