I have obviously failed to communicate this concept. I’ll try a something different.
Say SomptingGuy owns a log cabin. He moves in and decides that his log cabin needs a drywall interior and elastomeric paint on the outside to change it’s color inside and out. Log cabins, being made of logs, will eventually turn to compost. You can just imagine this happening looking at fallen trees in the forest or in your yard. Log cabins actually settle a bit every year as the wood naturally decays. There is not much you can do to prevent this. But SomptingGuy decides he wants a different color, and not knowing anything about log cabins, proceeds to paint the outside a very dark brown and install drywall, with a vapor barrier, on the inside.
SomptingGuy has thus created a petrie dish for the logs to cook in their own juices, hastening their decay. Compare this to putting your fallen tree into a compost bin. The decay will be sped up by the heat and moisture retention.
SomptingGuy decides to sue. His first expert, Big Structural Man, PhD, PE, SE and whatever else you would like to tack on to his name, has NO experience whatsoever in log cabins, but he's published lots of structural papers and is generally recognized as an excellent engineer and scientist. He has never even seen a log cabin, nor lived in one, nor built one. At trial, the attorney goes through Big Structural Man’s CV and asks all the pertinent questions, but Big Structural Man has to admit that even though he carries a PE in every single State in the US, he has no direct experience with log cabins. In fact, when he talks about log cabins he hems and haws and generally sounds very unsure of himself. He is a good scientist, but as such, he must admit that he does not have direct experience, except for designing a cantilevered balcony for a friend's cabin in the Adirondacks.
Thinking through the above scenario, SomptingGuy decides to interview a 25 year old architectural candidate recommended by his attorney. Turns out, this young woman knows all about log cabins. Her family has made them for 5 generations. She grew up in one and helped her father build a bigger one when their family expanded. They keep tabs on all the industry happenings and go to all the trade shows. They discuss the family business at the dinner table. When she talks about log cabins, she is direct and sure of her information and facts. She presents this information very well since she has been doing trade shows since she was 11 years old. Not only that, but she is a regular person, without lofty credentials with whom a jury can identify. She describes the compost analogy and the non-engineers sitting in the jury box instantly understand.
That’s all they have to remember. SomptingGuy plaintiff turned his own log cabin into compost, just like we have in the yard. We’ll give him a little money to cover his legal fees, but he will be out of luck on that $5 million claim to replace his residence.
The courts/judge/lawyer have no say in you selection of your expert, other than the requirement to disclose their name and CV prior to trial. You decide which expert is best for your case as part of you legal strategy.
If you think the letters and publications will sway the jury best, use Big Structural Guy. If you think the jury will like the other expert better, use that one. I'm sure you've seen cases where it's just one expert pitted against the other. If it all came down to who has the longer CV, testimony would be unnecessary. Just measure the number of inches of typed credentials.
"If you are going to walk on thin ice, you might as well dance!"