KISS
The solution needs to be simple to understand and follow or else it won't work.
After giving this more thought I now hold that RAND concept is sound at it's core. The main issues are:
a- subs, specifically newb subs in a vets RAND. The situation is all too familiar. The vet player is replaced by a newb. His nation, whether a strong empire or a humble kingdom is either quickly devoured or is extremely passive. Both ends unfairly impact the game result.
b- nation selection should be semi random.