As you proceed and your convoy grows (which is essential for some events and for you to get better cards) you will really soon reach a point where the food upkeep for traveling gets so heigh that you can't make it up, even with getting food in every single encounter (which is highly unlikely). For the three sectors that exist until now this isn't a major problem because you still can reach the end before food runs out, but as the game will get bigger you should consider adjusting the amount of food you will get from stronger opponents or/and add some possibilities to selectively dump the trash-followers you will eventually pick up. For now all the options to get rid of followers seem to kill of random followers (even when selling to the slavers, which seems illogical at least there the player should get to choose which ones to sell). Maybe you could add an option to leave some people at milestones or villages or create random events which will give the player a choice to leave a few people (maybe for good, like to help someone out, you could give a choice between some random "volunteers" sth. like: pick 3 out of 6, it would be the opposite process of recruiting followers).
Imo the disability to shrink your convoy in a controlled manner really interferes with the main and best feature of the game, the deckbuilding element.