@NemaisareRigby and Banny are both probably just a few seasons younger than Ellis’ own son, Grant. This makes it so that there’s probably a decently personal connection between him and all the young folk of the Abbey; he certainly feels at least part the parent to all after the death of his Adelaide. So between growing up a little behind Grant, and the taking of Adelaide by the illness she got, there’s 10000% some grandfatherly vibes going on. I don’t think there’s a dibbun in Redwall who hasn’t been chased out of the cellar!
Grant probably is the one who, once he got old enough to begin learning, would be the one to sneak safer ales to the other friends. Certainly no longer does this- but those two are in the age group he’d probably have included in his mischief.
I like to imagine old Tybalt the Vole is still alive as well, but is blind and pretends he can’t do anything anymore because of it. Certainly a source of sneaky dibbun schemes, that one.