Mars Coat King Spare Blade, 20 Blade Replacement, Extra Fine

What blade# tool would you recommend for nova scotia duck tollers (dense undercoat, silky 3-4 inch topcoat, frizzy long bum & tail hair).tx!

For my spinone italiano head & face i forget if breeder told me 10 inch fine or medium blade? what is correct for spinone italiano‽

The replacement blade (20) is smaller than original blade (20). How does this work?

Can i install this blade in my mars original coat king 16 blade handle?