Good points, the reinforcements are planned as you mentioned already. The mercenary idea I was not aware of before you sent me here to read it up. Thank you for the info.
The problem with the GUI is, I'd need it more dynamic, more flexible. Something like two panels: A vertical dynamically fillable bar - directly below the hero icon (with a gap). There I plan to put in the subordinates of the unit you currently control. The reasons for this are:To be able to see quickly the state of your direct subordinate armies. (and position)To be able to read messages up quickly and easily and to see immediately from which subordinate the envy was sent. (Okay, The government/senate for the Roman Republic also needs an icon as it also sents messages frequently.)To be able to send commands to subordinates quickly and/or answer questions (yes/no) in time for your military action not losing momentum.Another icon for requesting reinforcements (essentially a shortcut for an envy being sent to the headquarters! so reinforcements will need time to arrive. If they will be sent of course. And if they are not destroyed or delayed underway.).
The importance of the vertical panel below the hero is that we will manage that in a list/vector .. so that we can add subordinates and armies on the fly. Perhaps even have it as a tree, so to access the subordinates of your subordinates.
The fountain of health will be covered by our plan for adding water as a resource/requirement for units. Units as I foresee it and work on need both food and water in their baggage otherwise they may starve slowly. This means we will have an inventory, that we solve by reusing the already existing prop functionality.
Uultimately this will lead to real physical resources like swords, arrows, javelins. A unit can always bear food and water and will automaticall resupply at wells and oasis as long as it's safe (no crododiles, not attacked, ...).
A unit may only bear as many javelins as its force/strength stats allow. Speed will be calculated as a function of the weight a unit is bearing. Yet another level of detail for realistic strategy. Will you strip your units of water and of armour to make them manoeuver more quickly?
The trade post idea is interesting. Also that fog of war will be relieved in the independent traders' surrounding.
The free soldiers/mini cultures are possible too - as the AI currently in development will also allow own citizens to leave its tribe/AI out of frustration, essentially settling on its own until it is subdued .. or is paying tribute for safety. We have a decentralized AI, that is the decisions are made by the units, not a central magic power. (Of course the now independent mini culture settlements will also have its own AI, just the usual one .. even the colours of the old tribe they belonged to will remain for a while .. then slowly turning into Gaia's colours as time passes by.)
In my opinion our ideas are worth the effort. Still I wish to keep it as real and non-data/input heavy as possible. Hence the dynamic GUI proposition, so that it's not hardcoded ... will save a lot of time.
There is another alternative way to gain support by foreign mercenaries: If you subdued a foreign tribe, they will not only pay tribute, they will also follow into war. This might lead to a rebelion, especially if the expedition/defensive action is unsuccessful and the subdued people lost a lot of warriors. It could also turn out as putting aside a rebellion as the subdued state might no longer have enough trained troops to be confident enough to start a largescale uprising.
A more close relation to allies whom you can bring presents and send envoys is also planned to make them more easily join your activities or fight a rearguard for you should the invasion fail and turn into hastened retreat.