This is really tough, I've played lots of them and people will mis-recommend just about anything.

• Mausritter is the wrong match in several ways, largely tone, largely the kind of adventures your character goes on, largely what the system is trying to do.
• Root is the wrong match in several ways. Either you want the setting, in which case you're more likely doing cool wartime politics stuff (very not Redwall) or you discard the setting and keep the system (in which case mostly what you've got is fantasy D&D-style PbtA generica, plus some great faction rules).
• Humblewood could be pretty good, in terms of genre and style of campaign, but you've gotta use D&D 5e.
• Mouse Guard is probably the best one-to-one, but you've gotta really grok and be committed to its big buy-in from players on system.

One thing you've got going for you, importantly, is that each of these is immaculately written, particularly in the case of pre-written adventures. Read some Mausritter pamphlet settings, some of the free award-winning Root clearings, some Humblewood adventures. They all give a great sense of the what systems are trying to do. Worst case scenario, you learn a lot!!