It's been many years since I bought any Nubs...might still have a Cameroon and/or a Maduro buried somewhere...as I recall, they were consistent and predictable, as zz alluded to...they were short smokes being sold as robusto equivalents...not really
but nowadays, the only nubs I think about are the final remnants of cigars... the shorter they are, the more I liked them...pretty sure they'd be harsh, too, if I smoked them...
as Jake said, let them sit a while, to dry out...they may have been stored in a place with too much humidity which usually makes cigars harsh and difficult burns...letting them sit in a lower RH (58-65%) may improve them