I can see some possible use cases to handle mangled/obsolete formations:
An option to swap units with another formation to meet a template. This could also be used to quickly reorganize existing formations in the field.
An option for a training center to replace any missing units in an existing formation. Bonus points if the replacement cohort can be built for a formation that is at another location, to be transported and merged on site.
An option for a training center to refit existing units to a new type.
I think the refit and repair tasks which shipyards do could be a model for this.
You repair a formation by telling the GFCC what formation to start with and what you want it to end up as, it just builds the difference and adds them automatically.
I'm less keen on building replacement formations and shipping them around but it would probably make more people more happy if that was an option.
On an unrelated note, can we get a default Field Position for each template?
I don't think I'd ever want my artillery formations in the front line while the divisional logistics units want to be in the rear.
If I could have them automatically take up the appropriate support or rear position it would save a bunch of clicking.
A way of mass selecting and assigning formation position would also be nice and probably a good substitute for the above.
Also for STO targeting, could we get a default target or mass assign for them? (STOs designed as PD weapons are probably going to want one of the PD options)
Also the STO targeting tab would be better if you had the option to group them by system and body like the normal ground units tab.
Also could we get an option to target the closest ship?
Also (final one I promise) what is the difference between Final Defensive Fire and Final Defensive Fire Self? (I know what it does in the context of ships but I don't see the point for STOs)