Pre-Modern Military Formation Movement and Navigation

Hello, I am working on a prototype for a formation tactics type of game for ancient warfare (legions, pikemen, etc…), and looking into various solutions for formation pathfinding. All of the individual men in a formation of course can’t all just turn one direction or the other and start moving that way, but instead the whole formation has to wheel about so that as a whole the formation itself faces a new direction. Sometimes formations might move with a turn radius that is basically the same width as the formation, if that makes sense (ie men on the very inside of the turn march in place, and those on the far outside march quickly). Sort of like these:

at 1:45 :

and at 20:18 :

(look in the far corner)

It kind of resembles wheeled or tracked vehicle movement, but not exactly. Maybe a modification of some wheeled vehicle code might work, with considerations for about facing (ie all men turn around, rather than doing a full 180 wheel)?

Does anyone have a good idea how this might be done, with just having a single navmesh agent at the formation level (for performance and movement reasons), and the individual soldiers not navigating independently, but just being visuals that are kept in the same width/height grid the whole time?

thanks for any help

“but just being visuals that are kept in the same width/height grid the whole time?”

Just add them as child game objects to the formation game object? They will follow. And to simulate the formation thing maybe make the rotation speed very slow?

I am just planning on making my own first formation system, but i want it to be more dynamic. But I would probably save some cpu time if only one of the units would do the long distance navigation and the others would navigate themselves next to the leader.