I am interested in GMing this. I once tried to brew an organized redwall-themed ruleset for 5e, but that was too much effort for so little of results (pun not intended)
I will hurriedly read through your list of Redwall Races, and then be back with a Big 16. Or a little 16, as the case may be.
In the meantime, for those unfamiliar with the setting, here is a smattering of information about Redwall.
Redwall Abbey was built following the destruction and flooding of Kotir, an ancient castle in Mossflower Woods ruled by Tsarmina Greeneyes. Construction took more than 20 seasons.
The survivors of the Loamhedge Abbey plague came to Mossflower country, led by Abbess Germaine to start anew. She designed the blueprints.
Along with the woodlanders of Mossflower and other Loamhedge survivors, the Abbey was built out of red sandstone from a neighboring quarry, with the intentions for the building to be a place of peace for all.
A tapestry was woven in the Great Hall dedicated to Martin the Warrior. After his death, he was entombed beneath the Abbey.
While it is ordained to be a peaceful location, many times a warrior is called upon from the residents to combat a threat against this peace.
The residents of Redwall name the Seasons every year after some large occurrence. Young citizens of the Abbey are called Dibbuns.
The unwritten rule of Redwall Abbey is that "Redwall mice can go anywhere, through any territory, and pass unharmed."
Spoiler: The Abbey Charter
The Redwall Abbey Charter is as follows:
To be brothers and sisters of peace and goodwill while living together under the protection of Redwall Abbey.
Forsake all unnecessary forms of violence, not only to Mossflower, its trees, grasses, flowers and insects, but to all living creatures.
Help and comfort the dispossessed.
Harbor orphans and waifs.
Offer shelter to all creatures alike.
Give clothing, warmth and food to any beast or creature that is deemed in need of such.
Educate and learn, particularly in the healing arts, comfort the sick, nurse the injured and help the wounded.
Take food from the earth and replenish the land by caring for it; husbanding crops, living in harmony with the seasons always.
To honor and protect friends and brethren, only raising paw to do battle when life at Redwall is threatened by treachery and the shadow of war; at these times every Redwall creature should show courage, fortitude and obedience to the Father Abbot. The taking of another life must always be justified and never carried out in a wanton manner.
Spoiler: Leaders and Warriors
Total number of known leaders: 28
14 Mice: Germaine, Meriam, Bryony, Bernard, Saxtus, Vale, Mortimer, Mordalfus, Durral, Apodemus, Carrul, Lycian, Daucus, Marjoram
5 Squirrels: Arven, Songbreeze, Fenna, Perrit, Thibb
4 Unknown: Thomas, Saxus, Cedric, Furtila
3 Hedgehogs: Tansy, Phredd, Humble
1 Dormouse: Glisam
1 Otter: Mhera
Total number of known warriors: 13
5 Mice: Martin the Warrior, Dandin, Matthias, Mattimeo, Martin II
5 Squirrels: Samkim, Arven, Dannflower Reguba, Trisscar Swordmaid, Rakkety Tam MacBurl
2 Otters: Tagg, Tiria Wildlough
1 Hare: Clarinna
All of this information and more (links to individual characters both in and out of the Abbey) can be found here