My suggestion is to have formations for troops saved in a save game file or in some other file on the computer so you don't have to ever assign a formation for a troop you already assigned a formation to before unless you want to assign that unit to a different formation. This could be done based on memory of previous unit assignments inside party screen or based on encyclopedia>units formation option that could be added on individual unit encyclopedia screen.
For my case units without shield simply don't belong in the same formation as units with shield. I am a defensive player which makes me keep sorting units with shield from units without shield since enemy archers can decimate my army when units with shield and units without shield are mixed together and it is quite a tedious task to constantly assign formations especially after close battles with many casualties.
I would prefer to have my unit formations in order 1-shield units, 2-melee units without shield, 3-archers, etc. but that would be a lot of work to maintain and this also creates some problems with number 3 archers for example getting mixed with default 3-cavalry of other army members when leading or being a part of an army.
In that case when being part of an army but not leading it, AI commanders shouldn't use my formation assignment when leading the units but the default formations since in my case the AI commander charges in my archers which I have assigned to number 3 with default number 3 which is cavalry so AI commander treats my archers as cavalry so that is bad news for my archers. So when AI leads an army with me as a member archers should not be my formation assigned but the default one. When I lead an army however formations should remain however I assigned them to and not the default formations.
For my case units without shield simply don't belong in the same formation as units with shield. I am a defensive player which makes me keep sorting units with shield from units without shield since enemy archers can decimate my army when units with shield and units without shield are mixed together and it is quite a tedious task to constantly assign formations especially after close battles with many casualties.
I would prefer to have my unit formations in order 1-shield units, 2-melee units without shield, 3-archers, etc. but that would be a lot of work to maintain and this also creates some problems with number 3 archers for example getting mixed with default 3-cavalry of other army members when leading or being a part of an army.
In that case when being part of an army but not leading it, AI commanders shouldn't use my formation assignment when leading the units but the default formations since in my case the AI commander charges in my archers which I have assigned to number 3 with default number 3 which is cavalry so AI commander treats my archers as cavalry so that is bad news for my archers. So when AI leads an army with me as a member archers should not be my formation assigned but the default one. When I lead an army however formations should remain however I assigned them to and not the default formations.
