The engineering post is a critical one on any space ship. Not only is this guy tasked with making sure everything works, he needs to be able to find new and innovative ways to get it working after you broke it facing down the enchandi. Add him to the landing party or risk being unable to use the transmat to get back. And when the wormhole generator goes down, he's your guy.
You may want to keep an eye on your supply of sandwiches however.