First of all, really enjoying the experience so far! There is a great foundation for further growth. Have a suggestion here for companions.
With the current leveling system requiring "doing" actions to increase experience in that category, it is difficult to get companions to level their skills...
That makes sense to have them congregate. Maybe have a low chance that one will get scattered rather than return? (i.e. some may be captured and become separated). And if you didn't want to go find them yourself, maybe have a companion mission to go "Rescue _____"
I tend to agree that distances are nicely balanced, it seems to me that there is a "dynamic" start distance depending on the size of the army. Anyone notice the difference in start distance depending on battle size?