Here are the numbers of vermin in hordes and bands in the redwall series:
Blue Hordes: 7500
Corpsemakers: 4000
Rapscallions: 1000
Brownrats: about 900
Foxwolf Horde: 800
Gabool's Corsairs: 640
Cluny's Horde: 600
Sea Rogues: about 500
Thousand Eye Army: 400-500
Marlfox Horde: 400
Bloodwake's crew: 350
Wave Brethren: 320
Juskabor: 300
Kharanjul's Horde: 300
Ravagers: 200
Feral Cat Army of Green Isle: 200
Vizka Longtooth's Crew: 150
Gulo's Horde: 100
Grullba Deathwind's Horde: 100
Ravetail's Horde: 100
Bane's Mercenaries: 60
Raga Bol's crew: 50
Streamrats: 30
Slagar''s Band: 20
Burrad's Band: 12
Groffgut's Gang: 8
Driftail's Gang: 8
Sholabar's Band: 5
Wicky's Band: 3
(I couldn't find swartt's horde number)
Huh, interesting. For comparison, I'd guess the Redwallers generally had between a hundred and two hundred beasts in the abbey (though most of them wouldn't be fighting beasts), plus whatever Gousim or otter crews happen to help them out.