If there is a Preliminary Objection filed that states basically all or most of the points of objections then I think it would be better to just file a Joinder than a separate Objection.
I think that separate Objections should only be filed if one doesn't agree with the points made in the Preliminary Objection.
A Joinder is supporting what is being stated in the Preliminary Objection plus one can still add additional points of Objections in the Joinder that is not stated in the Preliminary Objection.