There is a set order that Food Souls get attacked in in battle, and it should be taken into mind in teambuilding (i.e. Choosing a Strength soul to buff up in case the Defense soul falls)

Note that there is an overarching priority: Defense > Strength > Magic > Support
(i.e. there have to be no defense souls present for the enemy's basic attack to focus on a strength soul to attack)

Also note that this only affects the basic attack (different from the normal skill) and skills that affect the frontmost/backmost food soul. (There are skills that specify "highest atk stat" and things like that)

This chart does not apply to Team Up, possibly due to different people contributing food souls, but more research is required.

Missing Food Souls
Defense Icon Defense None
Strength Icon Strength None
Magic Icon Magic Canele, Pizza
Support Icon Support Cloud Tea

This chart was compiled by Yorutoki, with help from the reddit and reddit discord server.

If you have any data or would like to help out, please message Yorutoki.

Most M Food Souls were not included as it is unlikely anyone would use them in battle strategically.

The chart reads from top (frontmost) to bottom (backmost).