I read a post where during trial, the defendant admitted the credit card and debt was theirs, and stated "I just don't owe it to this Plaintiff". That seemed risky also, but worked in that particular case.
That was me on both. The hearsay objection I can somewhat see a little risk. The one on standing I don't see any risk is that.
Your admitting the debt and asking the other side to show they are the ones that should be paid. It turns the table on your opponent because now they have to show the judge why they are not the ones trying to waste the courts time without the most basic of evidence, their right to even collect.
I guess like any trial strategy one should of course weigh the risk vs reward. I'm not tipping my hand and giving them time to make sure all there evidence is in admissible form and they have all their witnesses lined up. In my opinion it is the right strategy for me.
I've had a judge ask me when the last time I used a card was. I simply stated, "your honor were talking about an alleged account from several years prior and a Plaintiff I've never heard of until I was sued. I simply don't know due to the time frame of the allegations, the lack of prior knowledge of the Plaintiff, and the objections from the Plaintiff to my most simplest of requests during discovery.
In addition, while not put into my quote about hearsay, I did state if facing a summary judgement you might need to play the hearsay card sooner. The issue of standing makes all other arguments they might make moot.
In my opinion you can turn the tables on the other side and take away the home court advantage if you show the court that you're coming to court prepared and the other side is coming with inadmissible evidence.
Personally, I like to use the I'm just a lowly, non attorney pro se defendant with no formal legal training. However, I know hearsay and lack of standing when I see it. I don't think it's fair the other side is trying to get this past the court simply due to my non attorney status and perceived lack of knowledge of the rules of procedure.
The fact opposing counsel choose to assume they would be able to get inadmissible evidence admitted simply due to the fact they were facing a non attorney pro se defendant is no reason for the court to relax the rules of civil procedure to accommodate the lack of preparation from opposing counsel.