Here is my suggestion on how Influence and Adventurer could be modified. It would be interesting, what everybody think about this.
So, lets assume that Influence is the measure of how much a king is popular among the population. It means that Influence is needed to recruit troops, pioneers, henchmen, heroes, mercenaries. Indeed, who will join an army of a king who has no Influence? 
For this to work it needed that settlements should produce Influence, since only Prestigious Locations will not be enough.
How it works?
A player starts with 20 Influence and the first village-sized settlement produces 1 Influence per turn. Cities produce 2 Influence per turn and so on.
Every man in a trained unit requires 1 Influence to be persuaded to join the king's army. So it's needed 3 Influence to train the first unit which consists of three men.
If a king wants a unit to be trained in any of unit's traits, such as health, scout, strength and all other traits, this king should pay additional Influence for each trait to be given to a unit. So, as any magical item for unit requires crystals, all unit's traits require Influence. We all now that we people are rather lazy people and our king should really use some Influence to train us!
Clever henchmen already require Influence to be trained. It's only surprise, why any other troops don't require Influence to recruit.
Training pioneers should require much more influence than training regular troops. Or who will leave his village willingly? Perhaps 10 Influence per man in pioneer unit will be enough (total 30 Influence is needed to recruit a pioneer).
Of course champions also need some Influence to be recruited too. As well as regular costs in gold. Perhaps 10 Influence for a champion per his level will be enough. So to hire a 1-level champion only 10 Influence will be required, and 90 Influence will be required to hire a 9-level champion.
And here comes the Adventurer trait! I propose it should allow a king to hire champions for 0 Influence!!! But even Adventurer should PAY 100% for every champion he hires. Suppose that every champion likes an Adventurer type of a king and will join him even if he has 0 Influence, but who will work for free??? I don't know anybody of such kind. Even I while posting this text free of charge hope that developers will make my favourite game even better.
So, what we'll have in result? Unit or city spamming will be stopped, Adventurer trait will be more or less balanced. Resource like Influence will become useful. Perhaps Influence could be used Legendary heroes to make both games more compatible.
Perhaps new Influence system will bring new buildings to cities, such as courts, prisons and other buildings of law which will produce additional Influence.
What do you think about this?
