You can also remove a posture without replacing it with another one by selecting the formation HQ and opening the Unit Admin menu through the right-side panel, there will a button titled "Remove Posture" near the bottom.
ORIGINAL: Daza99
Why isn't number of workers we have listed on the left side? especially since it is a resource you need to construct things.
Is there somewhere we can find this number?
Workers are tied to your zones rather than the strategic headquarters. You can check the amount in a zone through the leftmost tab in the bottom panel. By default governors will hire and fire workers based on whether they're currently needed, but if they're having trouble recruiting enough you can change the recruitment policy by calling the governor and asking to adjust zone orders.
ORIGINAL: Daza99
How many miles is in a single Hex?
200 kilometers per hex, I don't recall the conversion to miles offhand. If you're curious about the scale for anything else you can check it in manual section 5.16.
Not affiliated with Slitherine. They added it to my name when they merged the Slitherine and Matrix account systems.