It's really not a bad way to go. You may still get reactions like you've come to expect from developers, but a sign of a good developer is whether after having that knee jerk reaction, they start asking about your technology choices and how you've implemented things. Essentially you want a generalist who is technology agnostic and is willing to roll up their sleeves and get to work in any codebase. PHP isn't that different from other languages and after a week spent learning the nuances with a little training help they should be able to be productive.