Clubs and greatclubs are pretty bad. Now I get they are meant to be simple weapons in the history of DnD but we've plenty of simple weapons that are both desirable or well off. Clubs do not get a +4 keen weapon, they don't even have a proper barbed slayer greensteel weapon variant with keen.
I have some simple (to me) suggestions about clubs (maybe greatclubs too) to sort of give them some value.
simple tweaks:
* Make club finessable.
* let them be -twohanded and finessable.
* make all of their recipes inherently have keen in the Masterly category (m-iron, m-steel, m-damask all are keen - do that with greatclub as well).
I don't have any item ideas for them but I think that'd help give them some value beyond throw away without revolutionizing them or changing their damage dice.