I love the setting of Brancalonia. I love the humor, I love the folklore, and I am currently learning Italian in evening classes to boot, so this is basically a perfect mix.
But I do not love that the authors picked D&D 5E as the rule system for this setting. Don't get me wrong, I find D&D 5E perfectly acceptable for heroic fantasy campaigns (and, in fact, I am running such a campaign right now). And I can understand this choice from a business perspective - it makes a lot of sense to tie your setting to the most popular RPG system out there.
However, Brancalonia PCs are not supposed to be great heroes, but fairly unimpressive never-do-wells. The rules deal with this by capping character level at 6, but I feel that this leaves the PCs with too little room to grow and removes much of the proper D&D experience. I'd rather use a rule system that was intended for weaker protagonists, rather than trying to distort D&D into something that is not.
So, what alternate system would you use for Brancalonia?
I hear good stuff about Blades in the Dark, but I'm not too familiar with it. I wonder if that would work.
BitD is extremely focused on thief/assassin gameplay. It's nicely setting-agnostic, but it isn't a system suited to rural gameplay.
I haven't looked into it but there are two other games that exist in the system. I immediately thought of "Band of Blades" which is a low fantasy bandit setting. It's an assumption but might be an alternative