The “I didn’t know because I was relying on my lawyers” defence is based in your own beliefs. If you don’t take the stand and testify under oath, then how do you make a strong case for your own beliefs? He’ll have to testify to be able to convince the jury.
They likely won’t go down this route in the end. At the moment they’re doing all this weird strategy selection by crowd sourcing. It’s a strange muddied online and via TV news discussion about how to do the defence. Then the echo chamber latches onto some ideas and the lawyers actually seem to take it seriously. That’s how they got the special master in the Judge Cannon case: Fox news pundits started demanding it so Trump’s lawyers went with it and since Judge Cannon is a right wing shill, she did too. It totally backfired since the special master was actually good at his job, but it all came together from this strange reality<=>social media feedback look the right has going on.