IC and Advice: Fire Emblem Inspired Royal Servants
Hi Caesar,
Sorry, I don't have time to be a player, nor have I had experience of the systems you mention, but the concept is similar to some ideas I've had, and I suspect the problems will be similar.
The biggest problems I see are with Scale, Time, and Player Quality.
Firstly, you're going to be working on at least two different levels - a personal level and a strategic level. You will need players who can cope with enjoy both styles of play. You will also need rules that can cope with both levels of play. Freeform may work, but it may abstract the action a bit too much.
eg, two armies are converging on the capital, which will get there first? Determined by GM fiat or mechanics?
Secondly, reconquest of a kingdom is an epic undertaking, and will take some considerable time. You will need players who are in it for the long haul. Also, you're going to have to balance the effects of time and distance.
eg. If a PC at court sends a message to a PC at the frontier, it may take weeks to get a reply. How much Personal Level action will take place whilst waiting for that Strategic Level movement? Are you going to play out that activity, or timeskip over it?
If these thoughts help you, I can add a few more or discuss in more detail. If such concepts don't pertain to your game, just ignore me. :)