Hi... as always i haven't read through all the 100's of posts, so if this idea has already come up - or is already planned then no harm done...
Been playing the beta a bit and it occurred to me that if we're going to have heroes in our service and want to form them into small parties it might be both fun and useful to have a tavern. The tavern/bar could be a simple interface button that opens up a panel and allows you to form the heroes into a group. You could then hit the "exit city" button and have the newly formed party move out of the city map and into the game map.
it would also be an easy place to manage your heroes and handle any training and equipping.
I only mention it as i play longer and longer games I have found I get more and more units in each city and moving them onto the map and keeping them in a group isn't easy (in the current state of play i find that one tends to head off by itself etc) and finding the character you want - Sovereign, Prince, Princess, Queen, Knight etc. isn't always easy.
Not sure if Heroes will be able to buy potions, armour etc. But this would also be a simple place to handle it.